Only the court wizards in major cities have them (Solitude, Windhelm, Whiterun, Riften, Markarth). And I've only ever found 2 out of the 3. Flying Spell and Flying Spell Companion. The Flying Spell Configuration isn't for sale, at least not in Whiterun. I add that spell using the console. Search in the console for "Flying". You'll see a SPELL called Flying Spell Configuration. You have to add it using player.addspell <id>. It is NOT an item, so DON'T use ADDITEM.
Good luck. Make sure you have a good clean save before adding this mod. It's glitchy as hell, but still way better than any of the competition.
Cannot Locate Spell Tome (5 comments)
Type 'Help flying'
That will show you the id code for the spells
then type player.addspell id
Good luck. Make sure you have a good clean save before adding this mod. It's glitchy as hell, but still way better than any of the competition.