The D90 has 2 command wheels...
OP, I didn't realize how big a deal the 2 command wheels were until I was teaching one of my friends who's just starting out. She has the D5100 (which lacks the front command dial) and I literally had no idea WTH to do while on full manual. The only cameras I've ever owned have had a front command dial (D90, D700 and now D3). I can say from experience that the D90 is an EXCELLENT first camera. When I purchased mine new in 2008, I had never touched a modern camera before, much less a DSLR. The D90 grew with me from that point all the way through launching a successful side business until this past January when I finally sold it to go full frame with the D700. I love that little D90.