Before you breed bettas you should research this topic from not only this site but many others as well. Remember that you can do everything right and still have no luck at breeding them so dont get discouraged after the first few spawns.
As you can tell, betta splendens are bubblenest builders. They will build nest with oxygen and spit. They can build the nest on the side of the tank, but most breeders find that natural set-up like floating plants or artifical styrofoam cups will work alittle better. After they spawn the male is the one who will take care of the eggs and it is best to take the female out. This can be found anywhere and for a reason.
But before you breed you should have a ballpark idea on the facts and economical and moral responciblity.
How much? ~ Breeding bettas isnt cheap. While some novice breeders will do it without spending much, arent really doing it the right way and have a miuch high unsucessful rate than breeders who do more research and do it the right way.
You have to start off with a tank. 10 gallons are probably the most common sized tank to breed bettas in. While you can breed them in smaller tanks, it isnt recommend unless you are a skilled betta breeder. A ten gallon will run about 8-10 usd. Make sure you get a glass hood or any hood. You will need a filter. It should be a sponge filter. A sponge filter is about 2-10 usd and worth every penny. While you might not use it right away it will help keep the baby tank clean. Live plants. Live plants are a must because they not only provide breeding materials but they also provide food for the growing fry. So lets look at a shopping list.
Tank = 8-10 usd.
hood = included.
sponge filter = 2-10 usd.
heater = 10-20 usd.
live plants = 3-20 usd.
styrofoam cup = 2 usd.
glass tube = 3 usd
55 gallon tank growout = 77-99 usd.
good breeding stock = 4-55 usd.
While their are other stuff needed, that would probably be the bare min i would get.
(More info on tank set-up and detailed betta breeding tips are on other pages.)
Make sure you have the time. Betta breeding requires your presences so that no body gets killed. Betta breeding can take anywhere from 1 - 7 hours so make sure you have the time to be there and watching. You will need time to take care of the fry. ie feeding and cleaning.
Make sure you have the money and time to breed bettas. It isnt for everyone and maybe thats for a reason. Please refer to my other breeding tabs above for more info on breeding bettas.