i'm pleased somebody wants to set up a darkroom in this age of digital!

before you start your darkroom make a floor plan of the room so you can more or less know how to layout the wet side and the dry side. are you planning on enlarging your prints? will you be processing b&w and color?
with this info you can allocate the equipment that you will put in.
must is a good exhaust system and plumbing and electricals.

if it's in the budget, construct a long sink made of 3/4" marine plywood and coated with epoxy that can fit at least four trays. over it, you can put a hood also made of 1/4" plywood where you can install the exhaust fan and the safe light for processing the prints (B&W).

i hope this will give you an idea to start your darkroom.