Just FYI:
Under section 609 of the Clean Air Act, only certified persons can legally
perform any type of service on automotive air conditioning systems. Also, refrigerant leaks are not always visible even if you know what to look for.
And if you do manage to troubleshoot the system and carry out repairs, you will
still need to pull a vacuum on the a/c system for at least a half hour in order to remove the air and moisture as these things can cause system failure. I don't suspect you have a heavy duty vaccum pump with R-12 fitting on it. After the vacuum, you'll need to fill it with the proper amount of refrigerant, preferably measured with a scale. If you are serious about wanting the a/c to work, take it to a reputable shop for diagnosis. Most places can at least tell you what you need or even fix it for you for less than $100.
I'm not trying to scare you away from working on your own car, but home a/c repair can usually will end up in disappointment for the inexperienced.