Here is mine. Its simple to build. I just used a pvc plug to block the intake, and an expandable rubber plug to block off the exhaust. Make sure the spark plug is tight too (don't ask how I know it'll cause a leak). Also you want to make sure the piston is at BDC when you do your testing.
The tester is simply a small brass TEE with a pressure gauge in the top hole, a schraeder valve (air valve like on a tire) on one end, and a barbed fitting on the other that is used to connect to a piece of fuel line.
Don't add air straight out of the compressor hose. Use a bike pump or a small transfer tank with only about 15 lbs of air in it.