NASW Code of Ethics. Please don't pay for this! But please do study it! It's a huge part of the exam.
The Social Work Podcast. Jonathan Singer teaches social work in real life. In webland, he teaches some more social work. Sometimes it's interviews with people in the field. Sometimes--early episodes mostly--it's a simple, clear, pretty quick walkthrough of some theory or concept you need to know for the exam. Price: Free.
Free Practice Questions. Posted regularly on the SWTP blog. Also there, not free, complete practice exams. Nice if you can scrape together some cash monies. Otherwise, price: Free.
Study Guide for the Social Work Licensing Exam. You do have to give them your email address so they can market at you a little, but for that (free) you get a pretty thorough 20-something page study guide that will walk you through what to expect on the exam, how to get prepared, and, maybe most importantly, how to keep your calm while getting prepared and taking the exam. Price: Free
Wikipedia. File under, "Not a newsflash." Once, Wikipedia was a semi-reliable source of mostly-great info about lots of topics. It's grown. Now it's a pretty-much-always-reliable source of very great info on just about every topic. Among those topics, the very stuff you need to know to pass the social work exam. Price: Free. (Though it's nice to make a donation or help out with editing, if you can.)
That should keep you busy. There's lots more out there. Especially on the info front (About.com, the Mayo Clinic). Search engines are your friend. Now let exam prep be your friend. Have fun with it. You're going to do great!