http://www.uesp.net/wiki/Skyrim:Skyrim

added link with the full map with all locations listed.

Saw a tip online...but the recent patch may have fixed it. I'm going to try it out tonight:

"If you're low on stronger types of arrows, like ebony or daedric, and can't find them frequently enough, you can pickpocket any npc's arrow supply that practices archery and replace it with one of your arrow of choice. They will then practice infinitely with your arrow type and you can take them from the practice dummy."

Skyrim level planner:

http://www.ign.com/builds/the-elder-scrolls-5-skyrim/create