Dear Dave and Marie,
Welcome to the adventure! I admire you. This will be an exciting time for you and your family.
Algebra is an incremental subject. That means you can't jump around from topic to topic like you can in science or other subjects. It would be best to settle on a program and stick with it. My favorite is www.teachingtextbooks.com, but many people say it's too pricey. You can often find used Saxon Math books, then supplement it with the teaching CDs located at www.diveintomath.com. They are excellent.
As for free, here are some ideas to get you started:
www.oldfashionededucation.com - look in the arithmetic section.
I hope these ideas help. Write again if we can help with anything else!