www.ultimatebettas.com is a really good place to do research.
Keep in mind that bettas can easily produce 200-300 offspring in a single spawn, and that you'll have to start separating out the males and more aggressive female pretty quickly to prevent fin damage (which will hurt your ability to sell them if that's your idea). I used quart mason jars back when I was breeding, and doing weekly water changes on 100+ of those once or twice a week is WORK! So I agree with setting up a barracks system if at all possible- if you reduce the amount of work, there's a better chance you'll actually enjoy it and produce healthier babies that grow that much more quickly.