Hey, Bookworm_Girl!
Thanks for your suggestions! I already have calibre and it has my books in it. I downloaded a lot of books from this website, Smashwords and another website that had free public domain books but I can't remember it's name anymore.
I got Adobe Digital Editions also because as I understand, I will need it to borrow books from the library.
I did not get the Sony Reader software because I read on the forums that calibre is preferred as ebook manager app and that these two had problems with each other, so it is recommended to use only one.
I am on Mac OS X if that makes any difference?
The idea about downloading the manual is awesome, I'll go do that right now! Thanks!