Wanting to build a garage (Need advice)

The one thing I was going to do, but forgot, was to put the blue stryofoam insulation down before you pour the concrete. It helps keep your floor warm in the winter! Make sure you have lots of plug ins, at least 2 220's as well for welder and air compressor. I built a seperate room off the back for my compressor room.
If you are going to install a furnace get one that you can hang horizontal and place it up near the ceiling. You will soon run out of space and the extra you make by hanging your furnace will be worth it!