How Villagers Breed
Trying to get villagers to have a baby is easy. To breed click and drag one villager over the opposite sex. They will sometimes be repelled by each other or embrace. If all goes well, they will head to a hut to be alone. The problem is that you won't be successful every time. Villagers who have their main skill to be breeding (check out the individual information by double-clicking on one) will be better at breeding.
Save time by checking the population count before you try breeding. If immediately after breeding the count goes up, then they were successful. If not, stop them from heading into the hut, and try again.
Quickly populate your village by setting a male villager to be a breeder. Shut the game off, come back in a few hours, and chances are your village will be packed.