I've completed the [Well Read] achievement and I'm currently working on completing [Higher Learning] for the nice pet reward, a [Kirin Tor familiar]!
It's taken me about 2 weeks to find 6/8 of the books and I've not exactly camped the spawn locations, only passed them by each time I've been in Dalaran. A guild mate found four of them last night which I think is very lucky. He called out that a book I needed had spawned when I was in Storm Peaks with my hearthstone on cooldown so I flapped my little druid wings as hard as I could and plotted my fall between the buildings so that I landed exactly on the stairs outside the guild charter room and got it just in time.
Here is a map of the book locations to help. I also found this guide that might help anyone do this achievement. I still need the book from near the daily quest giver and the one from the crystal teleport room.
Some advice, if you're waiting for the book near the daily questgiver don't just stand there, fish! I got [1000 Fish] while waiting for it last night. Just zoom out and tilt the camera so you can keep an eye at the box in the corner while fishing. For the other books, windowed mode is your friend. Split the screen with the book spot clearly visible to one side and some nice blogs or wowrelated sites in a browser next to it, an excellent opportunity to look for new addons! ;)