Lots to consider that you have not provided information for. Location is good to know for building codes, environmental/safety factors, pricing, etc, but I will weigh in with a few basics that you can consider in the mean time.
Size:
To start off, your measurements should be figured out in increments of 4 or 8 feet to reduce wastage (and cost) of the overall build, so 32x32. Square's yeild more surface area than rectangles if I learned anything in elementary school math, so that's something to keep in mind. You'll lose likely a 6" perimeter when you factor in wall thickness, so your usable space will be at about 31x31.
Lift:
If you are looking at a possible lift in your future plans, you're going to want tall ceilings which can be achieved in a couple of ways, either by having taller walls or scissor trusses (which allow for slightly shorter sidewalls).
Activities/Needs:
Clean/Dirty sides are a possibility, but that totally depends on the layout you choose to go with. It might be worth framing in a doorway into one of the external side or rear walls during construction so that if you choose to expand in the future, you can add a bumpout to house tools/parts/dirty work area/storage/etc.
If you desire a clean work area, it might be worth it to look into some style of industrial curtain rather than framing in a specific dividing wall. Interior walls are great for storage and tool location considerations, as they give you more attachment points and what not for hanging cabinets and lining with tools, but they come at the price of being pretty well permanent. Personally, permanence is not something I favour in a shop layout.
Air/Water considerations
Depending on your climate and temperature fluctuation you can "cheat" in a way by adding on an outdoor compressor room to keep the noise and floor space out of the main shop. You just have to route your air in from outside and put up a small lean-to off the side or back of the shop.
Run a line down the center of the ceiling of your main work area that at minimum contains air and electrical such that you can mount drop reels for air and electrical or lighting, possibly have a line (air and water) go to your roll up doors for outdoor air in the event that it might be useful (flat tire in the driveway or blowing out the lawnmower type stuff), and air drops along your bench.
Electrical/Services:
Preplan for a loop of wire every four feet or so, four feet up the wall. You don't necessarily have to put in an outlet every four feet but if you run wire to do so before you close up the walls, it's there if you ever want to change something. Plan your electrical layout with the future in mind, and take care to consider your lift placement, type and locations of garage door openers (jackshaft vs standard) and toss a few outlets in the ceiling for drop lights or cords (middle and or near door openings), and in near relation to your door openings if you plan to jackshaft openers.
Don't forget to document the build process and create a specific thread for that where we can follow along and provide advice/ideas/answer questions.
Cheers,
