You might want to look at http://interactmath.com. It’s done by Pearson Publishing and is meant to go along with the textbooks, but it’s usable on its own. Just log onto it, click enter, and pick an algebra book. Find what you want in the table of contents and then go work some problems. It has features that will work out examples for you and that will guide you through working a problem.
Used on its own, it’s not ideal, but it is a very good resource.
There’s a bunch of free resources at McGraw-Hill’s glencoe.com. You only need to enter a state and say if you’re a teacher, student or parent. If you’re in Illinois, this page contains links to free workbooks, reviews and tools. For example, this large PDF contains the current student workbook for Pre-Algebra according to Illinois math standards.
I want to second the Khan Academy suggestion. I have always been pretty much a math idiot. I never did pass high school algebra (although I aced geometry) and with all the moving around I did I still graduated. I’ve had a good bit of free time the past few months so I am moving through the lessons faster than most, but I’m already doing some advanced algebra I and some trig. By the way, I’m almost 50 years old.
Don’t just look at the videos, sign up and use the directed exercise plan. It takes you through various “units”. After some time has elapsed (days) it will put up units you have already “passed” for you to review and solve some equations so as to prove that you are still proficient in that section. While it’s not 100% I think it is well thought out. It does help if you have someone you can actually ask questions of and would no doubt work wonderfully for someone in school taking mathematics classes at the same time.
I can’t say enough good things about the concept behind the Khan Academy. It is still only a few short years old, but it is growing fast. While it is mainly math focused at the moment, the long term goal is to cover a myriad of subjects in the same fashion. The site is the embodiment of what the Internet should be about, I hope it continues the way it is going.
Wanted to add this, I began at the basics just because and quickly moved through them. However, I came across a couple of things that I was never taught. One was lattice multiplication, while very simple I thought the method very cool.