You should have the chicks vaccinated for Marek's Disease. You can have this done before they are shipped. The breed you choose depends on what you are looking for such as white, brown, or green eggs. Another thing to consider is personality. Yes chickens do have personalities.
Some breeds are friendlier and more docile then others.
Murray McMurray has a web site and will send a catalog as soon as you request it. Their catalog has pictures of every breed they sell and describes personalties and egg production. It also has a guide for starting baby poultry. Even if you don't order from them you will find their catalog helpfull. I was very pleased with them.