Litwin, et al's, Access Developer Handbook. They have 3 volumes sets for A 2000, A 2002; VBA, Desktop, and Enterprise. Each is very good for the topic covered.
I'd suggest the 2002 series, as Access is generally compatable forward, with each version adding additional capability.
Another is Access Cookbook, published by O'Reilly. It has many good programming examples for esoteric tricks which are very useful.
