What they said above. Google. Groups like this. Magazines. Even a few books. If you are lucky, you can find an honest, knowledgeable local shop that will hold your hand without emptying your wallet. Here in the Portland, Oregon (USA) area, we have such a shop at Iguana Micro. There are also local geek groups that take legacy donor equipment and package it into working systems for low incoming and charity groups. They love volunteers. These folks are golden at mentoring willing newbs.