Assassins Crossbow
Auriel's Crossbow
Bound Crossbow\Mystic Bound Crossbow
Companions Crossbow
Dawnguard Crossbow
Daedric Crossbow & Enhanced version
Dark Brotherhood Crossbow
Dragonbone Crossbow & Enhanced version
Ebony Crossbow & Enhanced version
Elven Crossbow & Enhanced version
Glass Crossbow & Enhanced version
Horker Crossbow
Hunters Crossbow & Enhanced version
Imperial Crossbow
Iron Crossbow & Enhanced version
Nightingale Crossbow
Nordic Crossbow & Enhanced version
Orcish Crossbow & Enhanced version
Practice Crossbow
Silver Crossbow & Enhanced version
Stalhrim Crossbow & Enhanced version
Staleddur Crossbow & Enhanced version
Stalneisti Crossbow & Enhanced version
Stormcloak Crossbow
Thieves Guild Crossbow

Assassins Bolt plus Fire, Ice, Shock, Flames, Paralysis, Soul Trap and Sub-Zero Versions
Bound
Companions including explosive versions
Daedric
Dagon
Dark Brotherhood including explosive versions
Dawnguard including explosive versions
Dragonbone, Dragonscale & Dragonhoned
Ebony
Elven including Sunhallowed and BloodCursed
Glass
Horker
Hunters with a fire version
Imperial including explosive versions
Iron
Nightingale including a poison version
Nordic
Orcish
Practice
Sliver
Stahlrim and varients
Stormcloak including explosive versions
Thieves Guild including explosive versions
Torch

Horker
Nightingale
Silver
Staledur
Stalneisti

Dagon
Dragonscale & Dragonhoned
Dwarven Explosive version
Horker
Nightingale including a poison version
Practice
Silver
Torch
Torch Empty

Long Bow is now craftable
Hunting Bow is now craftable
Hunters Crossbow and a Enhanced version add with hunters bolt and hunters fire bolts added
Assassins crossbow and enchanted assassins bolts added.
Crossbows and Bolts are added to leveled lists and can be found on enemies, sold at vendors and in some treasures
A Auriel's Crossbow and Bolts (Bolts can be crafted out of the special elven arrows)
A craftable and enchatable Nightingale Bow\Crossbow set (And poison ammo can be made)
Arrows and Bolts of Dagon (Think Mehrunes Razor ammo-style)
Horker Bow\Crossbow Arrow\Bolt
Specific Crossbows for the big Factions in Skyrim
Nigtingale Enchanted Crossbow as added rewards for the "Trinity Restored" quest
Torch Arrows and Bolts that light your way set enemies on fire
Visualized explosive bolts and arrows
Crossbows are distributed on a 1-5 ratio (20% chance)
CCOR, WAFR keywords and conditions are all included
Sliver bows\crossbows arrows\bolts that the Sliver Hand and Vigilants of Stendarr will use
Added Silver weapons do extra damage to all undead and werewolves
Balanced damage progression for all arrows and bolts
All arrows and bolts are faster and less effected by gravity
Proper Tweaks are included for better aiming and long distance shots
Stalhrim Crossbow and Bolts require the completion of "A new source of Stalhrim" to be completed before crafting
Edits all bolt recipes (excluding explosive) so that they match arrow recipes: 1 Firewood + 1 Material Ingot = 24 Bolts
Most crossbows have Enhanced versions you can upgrade them to after "Ancient Technology" is completed
Disables the Dwarven Crossbow, and Enhanced Dwarven Crossbow parts of the Ancient Technology quest
Disables Durak’s line about crossbows being a Dawnguard unique item
All material type keywords are included for proper smithing behaviors
Sorine will sell most of the types of bolts as you level
Massive tweaks and balances over the whole crossbow addition
Better textures for the original crossbows
HD Textures for most of whats included
Bolts and Arrows have been renamed (Arrow - Type and Bolt - Type)
Bash tags added
More in the changelog

Added Practice Crossbow, Practice Arrows and Bolts into the mod.
(Hint Practice archery items could be used to deliver poison without gaining agro from everyone)
Added Practice archery items can be bought from the Drunken Huntsman, Solitude Fletcher and Sorine Jurards inventory. 
Riverwood Trader has some Practice bows and arrows in stock.
Tonilla (Thieves guild) will sell Practice Bows, Crossbows, arrows and Bolts.
Practice crossbows do no damage and are relatively silent.Practice bolts do .001 damage (Just enough to make sound when they hit but not to agro)
Practice arrows now do .001 damage also (just enough to make sound when they hit but not cause agro)

The Assassins Crossbow is the most powerful crossbow there is.
It deals a whopping 30 damage at the base and has the chance to instantly slay your target.

However, the price to be able to make this bow is quite steep. You must achieve the following:

• Be a member of The Dark Brotherhood (Well, duh!)
• Have completed "Pieces of the Past" (To have enjoyed the company of Mehrunes Dagon)
• Have Completed "Trinity Restored" (To show you are a true friend of the shadows)
• You need to have the "Nightingale Archers Crafting Manual" in your inventory. (Its in the oath room of Nightingale Hall)

You also gain the ability to craft the series of elemental bolts that assassins enjoy for their trade:

• A regular bolt of course
• Enhanced versions of the Fire, Ice and Shock bolts
• The Hellfire bolts that deals 30 damage in a radius for 10 sec
• The Hoarfrost bolts that deals 30 damage in a radius for 10 sec
• The Paralysis bolts that do no damage but paralyzes your target for 10 sec
• The Soul Trap bolt that carries Soul Trap

There is a small sampling of bolts in the temple of Mehrunes Dagon but you will have to make the bow for yourself!

Are you worthy?

To be able to craft the crossbows you need to have the crafting manuals (see screenshot section) in your inventory and read the instructions! Dawnguard and Companion crossbows require you to finish their story-lines respectively before you can see the crossbows in the crafting interface.

There are pictures in the images section that show you where each Manual is located and I have placed a chest of all the manuals in High Hrothgar as a backup. I have also placed a Crossbow of each factions type near each manual.

Adds a craftable crossbow, unique quiver and four types of bolts for each of the following factions: Companions, Dawnguard, Dark Brotherhood, Nightingales, Thieves Guild, Imperial Legion and Stormcloaks.

The Nightingales Manual can be found in the oath room of Nightingale Hall.

For the Dawnguard Crossbow you need to finish the Ancient Technology quest that gives you access to the advanced Dawnguard Crossbows.

For the Nord Hero Crossbow you need to finish the companions storyline and then talk to Eorlund Gray-Mane to gain access to the Nord Hero weapons. Nord Hero weapons can only be crafted at the Skyforge.

Forsworn have found that Horker Tusks make excellent Bows, Arrows, Cowssbows and Bolts. Thus they have begun to craft and use them.

The Vigilants of Stendarr developed silver Bows, Arrows, Cowssbows and Bolts to further the fight against undead. 
Silver hand spies found this out and realized the side effect of extra damage to werebeasts and adopted the creation and use.

As a extra reward for completing "Pieces of the Past" Mehrunes Dagon imbues you with the ability to create arrows and bolts that contain his essence and have a chance to instantly kill your enemies.

There are now variations on the Stalhrim set from the second Skyrim DLC, Dragonborn. Stalneisti (Meaning Steel Spark in Icelandic) and Staleldur (Meaning Steel Fire in Icelandic) both come in Heavy and Light armor and includes all weapon types and arrows. Staleldur items have a light red tone, while Stalneisti has a deeper purple coloring. Similar to the Stalhrim set, these weapons and armor give a 25% enchanting boost for their assigned element. You have to have completed "A new source of Stalhrim" To be able to smith these items. The ores are added to leveled lists for the blacksmiths in Solstheim at lvl 30 and Baldur in Skaal village has a respawning barrel at his smithy that contains Stalhrim, Staledur and Stalneisti ores. 

With one arrow or bolt you will be able to:

• - Light up the area your arrow hits (to see better in dark dungeons or dark nights)
• - Set enemies you hit on fire
• - Set flammable oil puddles, flammable gas, and beehives on fire by shooting them
• - Lay short-lived fire traps that damage enemies with leveled damage where your arrow lands

These arrows are meant to be mid-level items, but should still be useful at higher levelsFires that are attached to the ground, wall or ceiling will last 15 seconds (10 for bolts) and then snuff themselves out. 

The light radius of the fires is slightly bigger than the vanilla torch.Note: Fire trap DOT operates based on tiers according to the level of the owner (the one who fired the arrow/bolt) AND the level of the target. 

For example, if the owner is in Tier 3 and the target is in Tier 5 (higher level), fire traps will do Tier 3 damage to that target. If the owner is in Tier 7 and the target is in Tier 2 (lower level), then the Fire traps will do Tier 2 damage to that target. Basically, damage is always scaled to the lowest leveled actor involved, to prevent the a low level NPC or player from punching above their weight class, while allowing the arrows and bolts to scale with the player. 

Fire from bolts does slightly less DOT than arrows

Arrows may be found in shops (most reliably in the Solitude Fletcher's shop and The Drunken Huntsman in Whiterun) for purchase, or may be looted from Bandits or Imperial guards/soldiers (if a town is under imperial control, the guards may have Torch Arrows)

Bolts may be found on some Dawnguard NPCs, or for sale from Sorine Jurard's shop

To craft the arrows, you will need- The book "Fihada's Research Notes" which can be found or bought in the Fletcher's shop in Solitude.

To craft the bolts you will need

• - Steel Smithing Perk
• - The note "Isran's Instructions" which can be found in Fort Dawnguard, on a bookshelf near the forge or bought from Sorine.
• - Steel Smithing Perk
• - Access to Steel Bolts (you get this during the Dawnguard Quest)

The recipe to make a bundle of 24 arrows is
- 24 x Steel Arrows
- 1 x Dwarven Oil
- 1 x Fire Salts

The recipe to make a bundle of 24 bolts is
- 24 x Steel Bolts
- 1 x Dwarven Oil
- 1 x Fire Salts

Auriel's Crossbow and Bolts:
The items are placed in a chest in front of Auriel's Statue / Temple in the Forgotten Vale (see screenshot). You will get there on the Dawnguard questlines.

Dagons Bolts:
At the end of the "Pieces of the Past" Quest when you can enter the shrine there is a chest with Arrows and Bolts of Dagon in it.

Artifact Bows:

Shadowswift nocks arrows 50% faster than any other bow, deals 50 bonus damage when sneaking and is found on the dresser in Astrid's room in the Falkreath Sanctuary. Should also be accessible to anyone who has already completed the Dark Brotherhood questline. 16 base damage.

Dragonslayer deals 40 bonus damage to dragons, 10 bonus damage to anything else and is found in Sky Haven temple, on the same table as Dragonbane. 20 base damage.

Blackreach Bane deals 50 bonus shock damage to enemies and a further 25 shock damage to dwemer automatons and is found in the Tower of Mzark, just before entering the room with the scroll on the right. 15 base damage.

Spectre deals 15 un-reduced bonus damage, banishes summoned daedra, turns raised undead and traps the souls of those it slays in a soul gem. It's found on the enchanting bench in the Arch Mage's quarters in the College of Winterhold. 14 base damage

The Medusa has a chance to paralyse targets for 6 seconds and deals 30 stamina damage. It's found on the table in Riftweald Manor next to the bust of the Gray Fox. 15 base damage.

Immaterious slows targets, and deals 5 poison damage for 15 seconds. Has 22 base damage and can be found in the hidden treasure room in Reachwater Rock that opens after the boss fights finish.