Welcome to the wonderful world of chicken raising, and
I'd recommend getting baby chicks, since they're so cute and it's rewarding to watch them grow into their beautiful adult selves.
Also, I cannot stress this enough:
Do your research beforehand to determine which breed would best fit your family's preference, situation and needs. Some breeds make better pets than others. Your more mellow breeds will be more of a pleasure to raise. Some breeds can be aggressive, flighty and crazy and hate human interaction.
Here are some breeds who people swear by as far as production, temperament and resistance to climate:
Australorps - they're sweethearts, very sociable to people, adorable and set the world record for most eggs laid by one bird - 364 eggs in 365 days.
Orpingtons - they're great egg-layers, have calm, mellow personalities, tame really well and have very soft feathers.
Easter-Eggers - Okay, so this isn't considered a "pure" breed; EEs are a mix of Ameraucana/Araucana and any other bird. They lay beautiful eggs that can range from blue to green to pink, and people say they're the sweetest birds in the flock. A lot of people on here love their EEs.
Sussex - they're very good egg-layers and they have a lot of personality to them. The speckled varieties have especally beautiful feathers and they make good pets. They're also quieter than most breeds.
These are just a few breeds to consider. Good luck on your endeavor, and happy chicken raising!