I just ordered my first DSLR Nikon D40 today and it won't come in until next wednesday. Am already really antsy wanting to get at it. What are some things i can read up on about the D40 until then? I already have a decent understanding of shutter, fstop, and iso jsut need to practice with it now. WOuld like to learn more about the D40 specifics until I can get my hands on it. thx.