Infinite Adventures is a new work in progress that seeks to add many new dungeons with unique custom rewards. Each of the dungeons is to have a backstory, traps, unique puzzles, and most have a bossfight. A teaser is already released on TESSource.
However, it's not just for one group to go at alone. The unique thing about this mod is that anyone can contribute a custom dungeon to this project, with the ability to get it involved in a reasonably larged sized mod, and with the creator having the option of not having to do the scripting for the traps, puzzles, bossfights, and rewards. The only requirements is that a complete layout is submitted, lit and ideally cluttered appropriatly. A back story should also be submitted, keeping in mind it will be edited to fit within lore as needed.
So how do you get to determine the content in this mod? First, build a dungeon. I highly suggest using the elderscrolls wiki to explain it to you, if you're new. It's actually pretty easy to get a decent sized dungeon done. Next, light it and clutter it as you see fit. Finally, briefly jot down in a text document your idea for the backstory of the dungeon, and what traps, puzzles, enemies, and bosses you think would be involved in this dungeon. Keep in mind that these may or may not make it in depending on the feasability of their addition to the dungeon. I can't mod the impossible.
Finally, send it all in a .rar file (or .7zip, if it's a huge file :P) to Cid89 on the official forums via pm. I suggest rapidshare for hosting, though it's up to you.
The released teaser has example puzzles, traps, an example bossfight, and a fun reward, a rideable dreugh which you can cast On Self spells from.