I might be a wet blanket, but I think you should start with a very small bunch and make sure you enjoy chicken keeping before you get into it on a larger scale.
They do require a commitment of time, money, and care, and you should make sure you enjoy the responsibilities as well as the rewards of it while it's still a small scale hobby undertaking.
If you should decide not to stay with the hobby, you can easily sell or butcher your birds, or at least give them away. It might be harder if you have a large flock on your hands and find it to be too much for you.
Also, without knowing what aspect of chicken keeping you are interested in it's hard to advise you much more. Generally, if you want meat birds or layers I would still advise getting from 3 to 6 birds. This way you should end up with at least 2 healthy birds, and hopefully pullets if you buy sexed chicks. That would only matter if you aren't raising meat birds or have issues with keeping roosters, but I ramble on...
Personally, I am planning to get into incubating and hatching my own chicks, but I bought 4 broiler chicks the other day to kind of ease myself back into chicken keeping. So far the birds are doing great and have reaffirmed my lifelong love of chicken keeping.
These little guys will hopefully make for a few great chicken dinners this summer.
My sister and I are also planning to buy about 100 broilers to keep at her place!