When can my son start preschool exactly?

I think he would be considered in the 3's class, which preschool at this age really isn't necessary. I am basing this on the fact that he will be 4 on November 2012, correct? If so, then he has missed the 'cut-off' dates for school. Most kids do benefit form a part-time part-day preK program when they are 4, the year before they start public school. I think the Kindergarten cut-off is September 30th must be 5. We have two in our house with Oct/Nov b-days, and they started school much later, 5 going on 6. Contact your local school district, they have an Early Childhood Office that can help you more. Avoid 'preschool programs' that run as a full-time day care center. This is not what a 3 yr old needs, nor a preK4. Most good preschools are free-standing, and have been in business for years.