You have several decisions to make. This is a wonderful site for all sorts of information, from what breeds folks like, to how to raise them successfully. It is excellent you are preparing ahead of time; you will be much happier with your results.
Red stars, cinnamon queens, red comets, and some other names I can't think of at the moment, are hybrids and will not breed true. Hatcheries cross two breeds for egg production and to be able to sex them at birth by color. If you want to establish a good home flock, you might want to start with pure breeds and evaluate from there.
Someone mentioned Barred Rocks being temperamental, but others on here have the same breed as beloved and gentle pets. Same goes for Rhode Island Reds. My experience is that RIR tend to be a lot meaner than BR, for example, whereas Australorp, Sussex, and Orpingtons tend to be docile or even friendly. Point is, this is only determined by breed to a point; they are individuals. Especially true for the roosters, which can be intolerably mean, or the sweetest of pets, and good flock protectors, too. Leghorns are usually considered the best layers, but the dual purpose breeds will lay nearly as well, and Leghorns are one breed that is almost universally very flighty, nervous, hard to handle, and definitely unfriendly. (There are exceptions, of course.)
If you get hatchery birds and want some experience with different breeds, Mahonri's suggestion for a hatchery mix like "rainbow layers" is an excellent one. If you order something like this, say 25 females, you will get a few roosters anyway, because their sexing is not 100% and because they will probably throw in a couple of extra roosters. Then you can choose which are the good roosters and which breeds you want to breed, or whether you just want to let them mix breeds and have "mutts." (Nothing wrong with mutts!) You will only want about one rooster to 10 or 12 hens, anyway. Which leads to another consideration. If you hatch chicks, whether under a broody or in an incubator, you will end up with extra roosters. This can be quite difficult to deal with unless you either eat them or don't mind selling them to those who will.
"Dual purpose" breeds are traditionally considered to be good for both eggs and meat. Barred Rocks (actually Barred Plymouth Rocks) are indeed one. Others are Orpingtons, Rhode Island and New Hampshire Reds, other Rocks, Sussex, Australorps, and more that I can't think of at the moment. Browse some of the big hatchery websites like Ideal and McMurray, as they will group the breeds for you so you know that Leghorns are really only good for eggs (they are small and skinny) but Orpingtons are dual purpose. The dual purpose birds will lay just about as well, if not as well, as the sex-link hybrids like red stars or cinnamon queens.
And do look over the Henderson's chart someone already linked for you. Lots of good information there.
Good luck!
