Nikon D50 Lense on ebay
 

I havent a clue when it comes to lenses. I was at the Zoo today and many of the animals i could not get good photos of until they came very close...which lots of them refused to do.

While i was there i noticed lots of people with the same camera as myself,yet they had larger lenses.

http://cgi.ebay.co.uk/Nikon-70-300mm...QQcmdZViewItem

Ive noticed this lense on ebay which is very cheap, yet im not sure what sort of distance or use this lense would be good for and is it worth buying for things like photography or distance photos?

Well Ben, For photographing captive animals, a 300 mm is often very much suitable. However, its worth taking into account how close you can focus too. especially when photographing things in the cases. Close focus with that lens is 1.5m/5ft.
I can't tell you much about the lens itself being a canon and sigma lens user, but I was unable to find any info on the nikon site on it.

I own a Nikkor 70-300mm VR (vibration reduction) lens. If you don't have VR (the one on eBay doesn't seem to have) you'll definitely need a tripod or monopod to get good distance photos. I find the lens kind of slow when trying to shoot birds in flight, that is it takes too long to focus and unfortunately birds in flight don't hold still. Hope this helps.