I use a Nikon D40 SLR, so I would say go for the Nikon as they are pretty easy to use if you are new to SLR's, plus they have many auto functions in which the camera will auto select most of the settings.
If however you are feeling adventurous, then the Nikon has plenty of manual functions which is what I like about them, plus you can get lots of instant data back about the image you have just taken and adjust within the camera, before even editing in Photoshop, etc.
I have never used a Canon so cant really comment on that, but it's probably a good idea to see if you can get hold and try both of them, and see which one you like the feel of in your hands.
Here's some pics I have taken on my D40, so you can see the quality of a SLR:
http://www.e90post.com/forums/showthread.php?t=453992