Can I p the CCNA using the Testking test package?

I just switched careers and I am now a network administrator, but my knowledge of networks is still limited. I was thinking of taking four prep cles at a local community college to prep me for the CCNA. However, I've heard people talk about Testking http://www.testking.com/640-802.htm and I was wondering if it would be better to buy the test package and prepare that way rather than taking the four cles. I also bought some introductory networking books from Cisco and am reading them. Will these books and the test package be enough?