I would recommend Canon. It is more widely available than Nikon and lenses are easier to find. Nikon is a great system but tends to be a bit more expensive.
Try to get a DSLR or SLR (digital or film) in a 35mm format. This format gives more flexibility due to the ability of interchanging different lens sizes.
For beginning photography the Canon Rebel series is a good choice.
www.bhphotovideo.com has some good choices.