I've begun studying for both CompTIA's A+ and Linux+ certs. The CompTIA A+ Complete Study Guide is the book I have, I'm not sure if I should read it cover to cover. I've been around computers for many years going back to 1996. In high school in 1990 I took a BASIC course. So far I've taken the pre-assessements for both A+ modules, and averaged about a 65%. I'm very weak on networking, right off the bat.