I have tons of both Nikon and Canon film and digital gear.
3 Nikon Bodies, 3 Canon Bodies, about 12 lenses total.
Both Nikon and Canon make perfectly acceptable DSLR's. My take-everywhere camera is a 4 year old Nikon D50. In my experience, the Canon shutters are quieter. My Nikons have slower, but more reliable auto-focus.
The 2 best good investments you can make:
1. A GREAT QUALITY bag that is cushioned enough to protect your gear and light enough that you can carry it around all day.
2. A tripod or monopod. Carbon fiber is expensive, but much lighter.
(As a bonus suggestion, regardless of what brand of body you get, spring for a 50mm/f1.8 lens. $100-125 or so, and essential for low-light photography. Your least expensive option in a prime (non-zoom) low-light lens.
Also, never buy grey market (not intended for US sale) stuff. You might save a few bucks, but not having a warranty isn't worth it.
PM me if you need more advice.
Example pics taken with my D50
http://www.facebook.com/album.php?ai...6&l=574b4eaa24
http://www.facebook.com/album.php?ai...6&l=9b72703b62