|MadSci Network: Astronomy|
have information on Ursa Major, and legends/history surrounding it. I've found that many common skywatching books have a historical overview of all the major constellations, and most have fascinating stories behind them (usually associated with ancient Greek myths). You should be able to find and cite as a reference any skywatching or stargazing book from your library or at a local bookstore. Most bookstores (Barnes & Noble, Waldenbooks, etc...) typically have a good sky reference on their sale racks for $5-10 if you're interested in actually knowing your way around the sky. Just a little reading and you can get oriented to what's up there pretty easily, and the historical information in the back of most of them (they generally follow similar formats, with a section on the origins of names for constellations and planets in a separate section) can help you with your report. You should attempt to give these books a proper reference (end notes or footnotes).
Try the links in the MadSci Library for more information on Astronomy.