Some folks start with a pair. What exactly are you trying to accomplish? That is probably the first question that you should ask yourself. I think the best advice is what @big medicine always says. Hatch a lot and cull heavily. So, if you start with 5 pullets, you can probably put 20-25 eggs a week in the incubator. Depending on your hatch rate, you should have 100 chicks hatched in about 6 weeks or so. Then you spend a lot of time and money on growing out those that meet the minimum requirements (feathered feet, head size, etc) and cull as you move along. Hopefully by the end of the year you have a fairly good selection to choose your next breeding group from. And then you do it all over again.