What is your experience with farming? Have you done anything to this scale before? CSA requires a lot of planning, succession plantings, great marketing, and a million other things.
My suggestion would be to visit another CSA and talk to them directly, get a feel for how much work goes into putting that box of food together each week... put in a little time working during harvest days, washing all that produce, packing it up etc.
Are you doing a meat csa, produce csa, milk, cheese... ?? A little more information about what it is YOU can do would be helpful for me to form a more honest reply than just " I want to start a CSA, how do I do it".