There are two main reasons you should not have bred.

1.) You obviously weren't prepared.
2.) Your bettas are veiltails.

But since you've already done it, I reccomend Atison's Betta Starter. Live foods such as Microworms, Vinegar Eels, and Baby Brine Shrimp are also important. Sponge filters are good for the first month or two of the babies' lives, since they don't have powerful intakes and can aslo work as an air bubbler.

I think Ashley's pretty much covered the rest.. Next time, be sure to do some more research before breeding!