When looking for a used lens on ebay how do i know if it fits my camera can i tell by the numbers or what and should I look for anything else on them.
Any Nikon lens with the "F" mount will fit your camera. Most lenses, on eBay for Nikon, will be the "F" mount.
However, what your camera will not do is auto focus with older Nikon AF lenses. You have to get the newer AF-S lenses if you want to keep auto focus and not use manual focusing. If you don't mind manual focus then your camera still accept and will meter correctly with the older "D" type AF lenses. Just no auto focus.
Even older lenses that were manual focus only, for older film SLR cameras, will fit and work on your camera but you will lose auto focus of course, as well as any metering capability.
So, to sum it up, look for Nikon AF-S auto focus lenses to keep your camera as it was designed. Other brands such as Tamron and Sigma also make lenses that work with your camera but they are not called "AF-S".