The Elder Scrolls V: Skyrim Glitches

Unlimited knowledge! I mean, gold.
Travel to Winterhold (carriage, horse, foot, fast travel, whatever). This might take a while.
Once there, continue down the road until you see an opening to your right. Travel up the hill and keep heading straight until you reach Sightless Pit, which is a bit to your left. Don't go inside, walk around it and climb up the rocks. You should see an altar.
On the altar is a skeleton and a book called "The Doors to Oblivion". Don't pick it up. Leaning against the altar are boots and a shield. Pick those up.
This should wake up the skeletons around you. Remember the one on the altar though.
After killing them return to that one skeleton and open up his inventory. Inside should be the book from before. Exit his inventory and then take a look at it again. There's now two copies of the book. Every time you open the skeleton's inventory, another copy of the book is added, therefore you have an unlimited supply of books, each 50 gold.
You can sell them, and/ or read one because it's a skill book for conjuration. It's best to have a follower with you to help carry more books. Remember where the skeleton is though so you can find him again.

Note: On your map, Sightless Pit is quite a ways below Winterhold. It's below Azura's shrine to the southwest. Notice the distance between Winterhold and Azura's shrine; the distance between Winterhold and Sightless Pit is twice that. Hope this helps finding the place a little easier.