The D7000 is a rather complicated instrument compared to the D50. There are a few elementary (obvious) things to check, e.g. making sure the lens cap is off and that the settings on the D7000 body and lens are both alike, i.e. auto or manual.

The next stop is your owners' manual. Look at the diagram on p.3 and check out the pages cited for #10 and #11.

After that (as mentioned by others) there are several books which translate some of the owners' manual "Engineeringese". One that I have found useful is by David Busch (Nikon D7000) who has written many user manuals over the years (and gotten great reviews). If you look in Busch's book (see pp 143-152).

Another step you can take is to call the Nikon help line: 1-800-645-6689.

Good Luck!!