I never went past pre-algebra :) My daughter is 12 and almost in 7th grade math (pre-algebra). I have used BJU, A Beka ans Saxon. It really is a matter of preference through trial and error.
I am going to be switching back to Saxon because I like the the fact that Saxon goes up so high in levels. The price isn't that bad either!
It has been my experience with the math I have used that you do not (in any way) have to be a math genius to teach it. You learn soooooo much along with your child that you don't have to worry about it!
As you get higher in levels, like high school, you can perhaps get with a homeschool co-op for that and get extra help if needed.
There are a couple ways to research, try seeing if there are used homeschool book sales in your area (there is a couple big ones every year in my area) and go browse the books.
Go to rainbowresource.com or cbd.com and look at the math there, they have samples from the workbooks and teachers manuals and such you can look at.
homeschoolreviews.com has reviews as well....although it can be long winded but good info there.
Lastly, see if there is a homeschool loop (in yahoo groups) in your area and see if you can get together with any other moms to look at what they have!
Hope this helps you out!
Rachel