Garage to Living Space- HELP
electrical outlets, lighting, switches
plumbing - if a bathroom is needed
safe exit in a fire (a door or window)
drywall, paint, carpet, ......
Most building depts will be extremly helpful for homeowners in these situations. Most also has hand outs that will help you in your planning, permiting & design of the space.
Many, if not most, communities do not permit the conversion of garages to living space for a variety of reasons.
Best time to find out if yours does not allow such conversions is now...