I agree - go chicks. I have done both - we bought 1 year old hens the first time. It just seemed like the ones we raise from chicks live longer and are more friendly. Plus you have a better selection of breeds to choose from. This time we ordered a completely mixed flock from Ideal. I like Ideal because I do not have to order 25 chickens at a time - way to much for us. Just read up as much as you can and have a place ready for them (along with all of the supplies) a few days before they get there. They are really easy to raise and they will be laying quicker than you think.
The only pain to me about raising chicks is the pasty butt period - which lasts only about 3 days - and if you are planning on going out of town for vacation (have to have someone keep an eye on them - especially the first 3 weeks).