I'd stick with either Canon or Nikon beginner models. Other brands are good too, but their lens choices are much more limited. If you find yourself liking photography even more after you have a camera, you'll want to get more lenses,
and that's when the brand matters.
As for between Canon and Nikon, it's really your personal choice. Go to the store, ask for the beginner models, and play with them, see which one fits in your hand better and if you like their buttons placement. And whatever the
salesperson tells you, go home and do research. I found that most of the people I talk to in the store don't know the first thing about cameras, and can't answer some of the most basic questions. Like one time I asked a Sony salesperson if
the camera shoots RAW, and he had no idea what I was talking about and he thought I was insane.
I have both Canon and Nikon and I personally like Canon's button placement better. My hands are small and is hard to achieve some of the Nikon crazy button-pressing-combos. I really like Canon's beginner Rebel series. The
latest one is T3i I think. I have T2i and not only is it a lightweight superb camera, it shoots videos beautifully as well.