Deciding whether or not you want a male or a female dog is a huge part of the process when getting your family dog. Male dogs are typically more affectionate and need more attention. Females can be more independent and inconsistent with people. That's not to say that females aren't as loving or into attention, but they're more prone to also enjoy their "alone" time.
On the other hand, females are generally believed to be easier to train and stay more focused. Male dogs tend to retain their puppylike tendencies for longer, with some never really growing out of them.
Both male and female dogs can be good with children, but some say that females are a better choice because of their nurturing nature. Having your dog spayed or neutered is the responsible thing to do these days, so you shouldn't have to worry about reproduction.