|COLOR=BLUE | where would be a good place to get info about a/c and heating systems to replace or troubleshoot problems??

The FACTORY service manual for your year would be a great place to start, there is a large section on the heater and air conditioning, including a "flow chart" for diagnosing. If you need parts, try these people:

http://www.oldairproducts.com/catalog/main_default.php

If you could describe a specific problem you are having I might be able to help.