First, allot yourself about four weeks to study at least two hours a day. Breaking up the study into several chunks of time and distributing them throughout the day worked very well for me.
Buy a good textbook to study along with a college algebra CLEP guide. While I haven't usually used a textbook along with the guides for other CLEPs, I found that with this test it's very helpful. College Algebra Demystified was a good one for me.
Now is the time to apply yourself to your books. If you remember most of high school Algebra I and II, then only about 10 percent of the CLEP college algebra material will be new to you.
When you've finished with your book study, take several practice exams. Your CLEP guide should have two or three, or you can buy them online (Petersons.Com offers college algebra practice exams).
When you get at least a 50 on your practice tests, then you're ready to schedule and take your CLEP exam. You can test with confidence, knowing your hard work will pay off!