We just got a set of regulation-sized boards and matching bags from Victory Tailgate through Amazon.com. There's an enormous variety out there, but these boards are thick plywood, finished beautifully and the bags are sturdy and the correct weight. We played with them the first time this past weekend (they came Friday morning), and we are very pleased with them. For rules and regs, there's a website for the American Cornhole Association.
We had a portable set that folded in the middle, and it was fun, until we played with regulation boards. We really enjoy playing, so buying the new boards was fun. Even my non-sports oriented wife likes playing. The portable set is now in the back yard for the grandkids to play with and the new boards are in the MH storage bay.