OK. Here is my thought. Is this is the first time? If I were you, give him a petmart female betta to begin with. Let the male have experience first if you are not sure the male know how to breed.
Get black worms from California. Those worms are good for the betta. They will help the eggs get big with protein. Basically in three weeks, the female will be ready to breed again and she will carry a lot of big eggs. Make sure you feed the male too with worms. I know this will make the water dirty fast so change water always at least in other day.
It is good to put both in the jar to see each other for a week. Keep changing water every other day until the fifth day and you still keep feeding them with black worms. So in the seven day, the water is pretty nasty and get ready for a breeding tank. Release the male first before the female. Put her in a chimney to protect the male biting her. Get a plastic bubble wrap and cut a size of 2" x 2" and let the bubble side in the surface water and not the flat area.
Man, the male will build bubble like crazy. In two hours, release the female and put on a dim light. Fish need to be romantic too. LOL It is good to release the female from 6pm to 8pm.
The next day, she will be ready to breed with the male from noon to 6.00pm. If not, you still can let them stay for another day.
After lay eggs, take out the female and give her good food. Now let the male to takecare the eggs. As for me, i let the male stay there to take care the babies for a week or 10 days. None of the babies dies or eaten by the male.
Think about it, the original wild betta male are suppose to take good care of the babies. He is giving his saliva to feed the babies too when they are young. This will help the babies get the immune system into the babies to fight for disease. Another thing to remember that this babies will be better off in the future for them to breed too. Now you know why a lot of bettas you bought from breeder don't know how to breed or eating the eggs. That is my two cents. All my breeding, I just let the male do his job for 10 days and none of the babies been eaten. You have to trust the male and the male betta have to trust you too.
OK. Of course I have to feed the male too and the babies. Feed the male with his food and see if he wants to eat it or not. Don't polute the water. Feed the babies with boil hard yoke too. Make sure mixed well with aging water to the yoke. Use a dripper to suck the egg yoke water mixture and drip to the water and feeding the babies. At least 3 times a day. In 5 days after hatching or a week, you can started to feed the babies with brine shrimp. Make sure slowly file up the water level with the aging water. (get more pile of water stand by earlier.
Turn on an air spond so the water is circular. OK. this is for right now. Need to do something on my new hatching bettas babies.
Food!