I'm not trying to put you off Nikon, but if you put "user friendly" as your first criterion, most professionals and users accept that the Canon EOS range is more user friendly and "naturally" laid out. I can impartially say this, having used friends' Nikons. It's important too to bear in mind that when you buy an SLR, you're buying into the system. They all have unique lens mounts, which are often backward compatible, but lenses aren't interchangeable between manufacturers. (Sigma, Tamron and Vivitar all make lenses that fit other manufacturers- but only one specific marque!)
Canon are the only manufacturer to make an f1.0 lens. Yes, as an amateur you probably won't ever need to buy a 5000$ lens, but this wider lens mount, which communicates with the lens only electronically, means you get a much brighter viewfinder image. Also, Canon make tilt and shift and other specialised lenses which no other manufacturer holds the patent on. They were first (and still are best) for Ultrasonic lenses, super quiet and fast autofocus system. Their image stabilisation lenses are also world class. You buy into this EOS system with even just a basic DSLR!
Not only this, despite the large number of Nikons in use in the field, the camera system of choice with pros and especially photographers that demand a lot of their cameras, is Canon. They make plenty of consumer level machines, and if you buy even the most basic Rebel T1i DSLR, you will have manual control and access to arguably the best lens range in the world.
Trying not to throw too many spanners in the wheel- you could also try the Canon Powershot G12 or the G13 when it comes out... almost as well specified as their DSLRs but with a much more compact body and long range lens. I own Canon DSLRs but will be buying one of these babies as a backup for snaps and holiday shots- as well as to my more serious photography.
Used the Canon EOS digital and film SLRs for over 17 years.