Mon 05-Nov-12 09:05 PM | edited Tue 06-Nov-12 02:52 AM by Chris Platt
Upgrade. The D7000 is a remarkable camera. Use the same settings you use on the D90 for starters - center weighted metering, AF-S. It should feel pretty familiar.
Read the owner's manual. Buy another user's guide or two. Start playing with (and learning) the other modes. They give you an excuse to use the camera for nothing more than experimenting and practicing. You can always fall back to full auto or P mode if you're unsure of yourself in an important situation and don't want to take a chance on fouling up your pictures.