Anyone interested in taking the A+ and Net+ exams should buy the following books to help you study for the exam. I highly recommend these books. Its what I used in my college courses.
A+ Guide to Managing & Maintaining Your PC - Jean Andrews
ISBN 0-619-00038-4
Network+ Guide to Networks - Tamara Dean
ISBN 0-7600-1145-1
Hope you enjoy these books as much as I did. And good luck on the exams.