Will this lens fit on my camera?

I'm looking at renting a Sigma/N 4.5mm f/2.8 EX DC HSM Circular Fisheye for a couple of days to have a go at fisheye photography, but I don't want to commit to anything if it won't fit my Nikon D3000 DSLR.
Also, could someone tell me if this particular lens has an autofocus motor in it? I don't fancy the idea of trying to use manual focus when photographing a gig!

It will fit and autofocus according to this Sigma hosted compatibility chart.

http://www.sigmaphoto.com/...lity-chart

Fisheye lenses really don't need auto-focus, but don't worry, HSM = Hyper-Sonic Motor

Using the electronic rangefinder in the D3000 is not a big deal and you will find that at f/16 that lens has a depth of field from about three feet to infinity.

I have used the Nikkor 10.5 mm on an old Nikon D40 with no problems whatsoever.

You may want to add manual focusing to your photographic skills. Until about 30 years ago, All lenses were manual focus and it did not slow down photographers at all.

My guess is you did not visit the Sigma website to get the specs of this lens, is that right?

http://www.sigmaphoto.com/...heye-sigma

That kind of direct approach is usually a much faster way to get the information you seek, rather than hoping someone here has good information and be willing to wait for it.

You have a nice camera by the way.