Chris' advice is excellent, but it makes me smile.
Clearly, I have spent more time than Chris has in darkrooms that are smaller than 10' x 5' .
Bigger is however, better!
One thing to keep in mind though is that it is not absolutely necessary that the trays be in a deep sink - a water resistant table top with a small rim can work too. Just be sure to have a usable smaller sink or two (laundry tubs work) nearby.
Have you looked through the darkroom portrait thread? http://www.apug.org/forums/forum43/1...html#post84482