Here is some stuff that I wrote up ages ago on spawning Bettas. There is a lot of It, but it is good info!
I strongly recommend that you look over all the things required to properly spawn (a term that basically means breeding fish) a male and female Betta before deciding to go ahead and breed them. Here are some things that you need to consider.
1. Males and females should only be in the same tank together when they are spawning which means that you have to have two 3+ gallon tanks with filter and heater for each which can get pricey, and that isn't very much considering all of the other stuff you will need on top of that.
2. Bettas are not like live bearers, they don't usually get along very well, males have to be separated or they will fight to the death. Females are ok together, but there are those few females who can get very aggressive and cause lots of damage. That means that you need to have at least 50 (usually more)individual jars to put each Betta in.
3. During the spawning process there is usually fin nipping between the male and female and they need to be watched so that it doesn't get out of hand. This can mean that you have to spend a lot of time watching the fish, and unless you have the time to check the tank once every hour or so during the spawning which can last up to a day or more you should not attempt to breed your fish.
4. Spawning pet store Bettas is usually not a good idea because not only are they usually old and in bad shape, but there is a reason that they are cheap. Most pet store Bettas are your typical veil tail Bettas. There isn't anything wrong with that, but if you want to make any money at all off of your stock, then you need to start with another kind of Betta. Pet stores don't give you very much money at all for all of your troubles.
5. Quality Bettas aren't cheap! To get a quality pair from a reputable breeder like Faith at
http://www.bettatalk.com is very expensive! Her Bettas range from $40 to $150 each!
6. Spawning equipment is also very expensive! Here is a page from Betta Talk that will give you an estimate of how much breeding Bettas is going to cost you.
http://www.bettatalk.com/spawning_setup.htm
Now, I have spawned Bettas successfully and let me tell you that it is worth the work! I love it! I am not trying to say that you should give up the idea entirely, but you do need to consider the time and money requirements that are involved and then decide whether or not to breed. If you do this and think that you want to go ahead and breed Bettas than by all means say so and I will give you more info on that topic. You should also check out this web page:
http://www.bettatalk.com/breeding_bettas.htm
It tells you a bunch about spawning Bettas. I would also check out the rest of that site because it can really help you learn more about this wonderful fish! Hope all this has helped you!