The Nikon D800E has the best sensor rating at the moment..
( ....probably a little over the top for a first camera, haha.. )
But both Canon & Nikon ( & other DSLR brands ) are all good, it’s personal choice.
Without getting into the technical side of camera’s… it’s doesn't matter if you
Have a $400 or $4000 DSLR…. It’s how you use it that will give you the best results.
Here’s some of my favorite DSLR sites.
DxO Mark - Camera Sensor Ratings
http://www.dxomark.com/Cameras/Ratings
DxO Mark - Camera Lens Ratings
http://www.dxomark.com/Lenses/Ratings
Dpreview ( good starting point for reviews & looking up specifications )
http://www.dpreview.com/
Camera Labs ( another great site for camera & lens reviews )
http://www.cameralabs.com/
Pixel Peeper ( this site is very handy, select any camera or lens then click on
SHOW PHOTOS to see examples that combination has taken )
http://www.pixel-peeper.com/adv/?lens=13020
Fantastic Tutorial site
http://www.cambridgeincolour.com/tutorials.htm
Lens Reviews
http://slrgear.com/reviews/index.php
Nikon Lens Simulator ( see what you should expect from a lens before you buy )
http://imaging.nikon.com/lineup/lens/simulator/
Cheers..
PS: My choice.. Nikon.