Emily-Ryan,
A handy tip for finding cheap lenses, especially for Nikon bodies, is to find a Film SLR (alternatively learn using a film SLR, you'll learn a heap more, and I found the cost constraint made me think about composition in every shot), kit. They are usually super cheap, and Nikon DSLR bodies will be able to use the lenses in manual mode (which you'll be using anyway)...
Sno