Welp, buy a quart of oil, a compression tester, a 19mm 6pt socket, spark plug socket (5/8") a ratchet, and maybe a 6" extension for the sockets. Unscrew the plugs screw in the compression tester one at a time, and turn the crank over a good 7-10 revolutions or until the guage stops going up, do this with the throttle plate all the way open. If they're all close to the same number, the compression is good. If you really want to get into it, drop a cap full of the quart of oil into the chamber through the spark plug hole, and now check compression again. If it raises a substancial amount, say 50psi, the rings are most likely bad. A compression test should be done on a warm motor, @ WOT. But you can get close results on a cold motor.

 

Autozone would be a logical place to start.

If you're thinking about swaping a motor, you should already have the majority of this stuff. Most of which can be found in a basic socket set. You can pick up a great craftsman socket set for around 40 dollars. The compression tester is about 30. So for probably under 100 dollars you can get everything.