Farm fresh eggs are great, not to mention more nutritious. One reason to do it.
The basics: You will get about one egg per laying hen a day. This goes down in the colder months depending on the breed. Barred Rocks will lay more consistantly, but the more prolific layers are White Rocks and Rhode Island Reds during the summer months.
Other types to consider are Araucanas which have a blueish/green egg. Very pretty and great for Easter. Another common breed are the Buff Orphingtons.
When buying chickens you can purchase them as "sex links", which means they have been bred to be a specific color according to their sex. i.e. black chicks are female and brown ones are male.
If you setup a nice little system it's really not that big of a deal and can be really fun for younger kids. How much space do you have? You can either build (or buy) a mobile coup or a stand alone. Electric netting/fence is relatively cheap and a must to keep predators out. Dogs, cats, coyotes, fox, etc.
But yes the roosters annoy the shit out of me. Esspecially when the coup is close to the house for obvious reasons.
Chicks are very cute, but when they start to molt they become the most hideous thing in the world. Uglier than a Pontiac Grand Prix. But then they eventually become of laying age and are nice looking.
If you end up hating it..........turn them into stewing hens or meat birds easy enough. But overall I think it's pretty cool. Again I say this only when you have a properly setup coup. Given enough space you don't really need to feed them. Just provide water and cover and keep an eye on the young ones in the hot weeks of summer. You can lose up to 5% of them when they are molting.
It can be pretty educational for kids too. We use to have kids come over to the farm during lambing season all the time to watch the sheep giving birth, chickens running around and honey being harvested. 99% of the kids out there don't have a clue as to how their food ends up on their plates.
If you are just going to do a dozen or so there is not much work involved. You'd only have to clean out the coup once a month. The more time they spend outside (free range) the less mess you'll have to deal with. With that said free-range is the only way to go.
This is the ONLY site you need.
http://www.mcmurrayhatchery.com/