Do you want the camera to learn more about the DSLR features and functions or are you after a easy to use fun camera??
If it's the former, then go with a D70s, D50 or D80...
If you're looking for a small fun and light camera, then get the D40X. The differences are all in the user interface. If you can't get at them easily, chances are, you won't bother with them when you have the camera.
You need to play around with the Aperture, Shutter speed and ISO to have a better idea on how they correlate to help you get the desired picture. Else you may just end up with the Green button mode most of the time and frankly, it's gonna be a larger sized PnS.... :sweat: