Can i cook a whole rabbit in the crock pot or should I cut it up?

I would cut it just like you would cut up a chicken. 

Personally I would dredge it in seasoned flour then brown it.

It will be done when it is tender.  If it was a wild rabbit it might take longer as it will be a bit tougher but it will be lean. So it might get a bit dry.  

If you don't cut it up, it may take longer to cook. You'll know when the meat starts to visibly pull away from the bone. It will be very easy to cut up at that point.  You'll want to use some kind of sauce with some spices. Rabbit is on the bland side, by itself, the consistency is like chicken, with a similar but more 'gamy' flavor.

You need to cut it up, it will be cooking for ever if it's whole. The legs will dry out.

You can cook it whole in a bit of liquid (braising) for around an hour or till the temperature reaches about 160 degrees at its thickest part.