There are all kinds of Series 7 study materials out there. Of course, I'm somewhat partial to the ones I write and produce. But, other companies have good questions, too, and if you have them, use them.
If you are on a budget, I recommend getting the Pass the 7 textbook and the Pass the 7 ExamCram Online at www.passthe7.com/exams.htm (hit continue shopping, etc.).
If you're not on quite as tight a budget, get the full package at www.passthe7.com/fullpackage.htm. This includes the audio lectures on CD and the DVD set that you can watch on your TV, with the ability to pause, review, fast-forward, etc.
Either way, make sure you learn as many vocabulary terms as possible, and focus on understanding concepts/how things work. You don't get to memorize a bunch of bullet points and merely spit them back at the testing center--the exam forces you to prove you can apply the information you've learned in some pretty creative ways.
So, study hard, everybody. The Series 7 doesn't play.