How is this from a Nikon? The picture clearly shows a Minolta lens - it will either fit a Minolta Autofocus camera or a Sony dSLR, Unless you posted a picture of a different lens, there's no way this fits on a Nikon.
No worries ashley - email me if u have any questions, but this wouldn't be very useful on a Canon EOS dSLR - if you had a Sony it would be perfect! (@OP, you might want to add this info to your auction!). You can get an adapter that will physically put any lens on your camera, but you won't be able to use the aperture on it. It will automatically stop down to f22 all the time. Your best bet with a Canon EOS dSLR is: AF Canon EOS lenses or old Pentax screwmount lenses (if you want to go old-school). Asahi Pentax, Mamiya-Sekor, Yashica, and Practika (among others) made tons and tons of glass in this mount in the 60s and 70s. You'll be shooting manual, but you'll have the control you need.