It is up to you whether you want to worm your chickens. Any animal that has access to dirt should be assumed to have some worms. Small worm populations in a chicken's digestive tract cut down on feed efficiency a bit, but don't cause too much harm. It is only larger infestations that can cause problems.
If you ever see worms in your chickens' droppings, worm them. Otherwise, just go by what you think is best. Some people never worm, and others worm once or twice a year. You can worm at any time of year, and with nearly any age of bird.
Thanks everyone for the reply. Kelsie2290, the thread you provided was great. It seems like some people swear by worming and others find it to be only out of necessity. I think I going to take the wait and see approach. Hopefully it turns out to be the right choice.
Welcome to BYC. Glad you decided to join our flock. BantamLover21 has given you some good advice and Kelsie2290 has given you a great link, so I'll just say, please feel free to ask any other questions you may have. We are here to help in any way we can. Good luck with your flock.
Some people like to do it as a precautionary thing, and others have their birds on a schedule. Free ranging flocks are more susceptible to worms however. Just keep your eyes open for signs and worm if necessary.