To breed Betta's you need a healthy female and male, when a female is ready to breed you will see a small white thing sticking out from her underside (it's her egg tube) thats a good sign that the female is full of eggs, she will also have a plump belly.
Place the male Betta in his own tank (i have my temperature from 78F-80F, i also have no pump or air pump in the tank) and leave him to build his bubble nest.
Once you think he has finished building his nest place the chosen female near the males tank so they can see each other (i like to use a 2litre pop bottle, i cut the bottom off and take the lid off and place the female in it). The male should flare at the female and the female should flare back, she will also have vertical lines down her and be assuming a head standing position, this means she is ready to breed.
Release the female out of the bottle or place her in the same tank with the male. Don't worry about the male attacking the female this is normal, but if the aggression gets too much for the female then put her back in her bottle or separate tank.
The female will follow the male under his nest and will eventually spawn, the male wraps the female in his fins and they spawn. The male then picks up the eggs and places them in his nest, once the spawning has done take the female out.
Leave the male in with the eggs until they are free swimming, this normally take 4-6 days, (you can then place a low speed pump into the tank once the fry are free swimming) then you must take the male out of the tank or he may eat the fry.
Hope that helps!