Burt,
Get at least 2 books - Sybex CCNA Study Guide by Todd Lammle and another by Cisco Press - that will give you a very strong background in what you need to know to both 1) pass the exams and 2) work in the field.
As Burt said - setup a Cisco lab - at least 3 routers and 3 switches - it has been discussed in GREAT detail here - just read the posts and ASK questions.
Then as you read the subject - try the stuff you read about on YOUR routers and switches - LEARNING BY DOING!!!!! Learn how to make YOUR lab WORK, guess what - it will help you both on the exam and on the job!!!!!
Most of the books listed come with practice tests - use these to gauge what you need to learn BETTER - DO NOT MEMORIZE QUESTIONS AND ANSWERS!!!
Hope this helps!!!
E.A. Broda
CCNA, CCDA, CCAI, Network +