I started a while ago too and I pretty much learned how to stage manage just from reading everything I possibly could.
First off, read as many of the back-logged posts in theis forum as you can, you pick up so much information they're really helpful.
There are some really good books out there too if you can get your hands on them. My favorite is
The Backstage Guide to Stage Management by Thomas A. Kelly.
There are also lots of online resources that you can get to with just a basic internet search, I've listed a couple that I found helpful below.
Most importantly, talk to people at your school to find out how it works in that specific environment. As the others have mentioned, every theatre is different. The director would definately be a good place to start (what does she expect of you, etc) but TALK TO OTHERS WHO HAVE STAGE MANAGED AT YOUR SCHOOL. That is where you'll get the most valuable info for your situation.
Have fun and good luck!
Keep us posted!
SMs Do Make Coffeehttp://www.geocities.com/dollariquestnet/SMhandbook.html (online)
http://lukedemoss.com/cadownload/ (downloadable--it's the 20th link down)
Stage Management Without Tearshttp://www.theatreontario.org/content/publications.htm (again, it's about halfway down)