I'm a Canon whore, they roped me in with a customer service experience I had with them a few years ago. That's one thing I will give Canon, they offer very good CS.
As far as the DSLR bodies go, the main difference between Nikon and Canon........Canon lenses are more expensive. Nikon as Image Stabilization built into the camera body, Canon puts it in their lenses.
I have the T2i and have been very satisfied with it. I recently rented a 24-105mm L lens. The L series lenses blew me away compared with a non L lens. That being said, most of those lenses start at over $1000. If you are planing on shooting wild life, you will need an expensive lens to get the up close shots and a big zoom lens needs IS to make it clear or a tripod.
I would give Nikon a hard look if it were me. Your lens cost in the long run would probably be less overall. That's not to say the Nikon lens is a lot less expensive, but having IS built into a camera body means less moving parts in the lens.
Like mentioned earlier, get a good book. I have the Canon T2i for Dummies book and it was a great place to start. You learn about the camera functions and what each setting will do and you get a general introduction into DSLR photography. A have a couple other books that have been helpful as well.