I have been pushing DS' school to start a MathCounts team and they have agreed. However, the school in turn nominated me to "coach" said team, along with a school math teacher. I was a good math student (25 years ago!) but now work as a professional in a decidedly non-math field. (And my DH is exclaiming with some asperity "How in the world do you have time for this?" which is a very legitimate question.)

Can anyone recommend practice materials or resources to start a team from level zero? I know AoPS has an online MathCounts prep course and I assume it's good like everything they do. Is this true? Any other, less expensive resources anyone can recommend?

Thanks for any help with this!