Myth #1: "Public schools aren't as good as private schools."
First off, this is rather a meaningless assertion to begin with, since there's no such thing as a "typical" public school. Because the American public school system is decentralized, quality varies tremendously. The fact is, however, that, depending on what indicator you choose to use, many public schools outperform private schools.
It is important to understand that knowledge has no address. Knowledge does not "reside" in one location or another. In fact, now that the internet has broken down nearly all the average cost of daycare in northern virginia barriers that once limited information access, this reality is more true than ever. Your child can get a first class, quality education from your local public school.
Saying that private schools are "better" than public schools is a lot like saying that books you purchase from Barnes & Noble are "better" than those you obtain from your local public library. The knowledge, the access is the same. It's what you (and your child) do with the books that matters. Likewise, it is what you and your child do with your public school that will determine his or her educational outcomes.