As Golden Rule suggested that is a very good book to use to learn the fundamentals and concepts involved. It is very worthwhile to keep handy as it shows different guage readings and symptoms to use for determining the nature of your problem while troubleshooting with your guages.

To start with hook up your guages and see what your static readings are. If they are in the area of 80 pounds or so, then your clutch should kick in. If it will then go ahead and start up the ac full blast and see what the readings are after running five minutes to stabilize the system to get meaningful readings.

At that point, the book would be VERY useful in deciphering what you're guages have indicated to you. Since you don't have the book, post your readings and other symptoms here and we'll do our best to help you troubleshoot from long distance.

Good luck,