You have been checking the Web sites. Talking to friends. Maybe you have even been on a conga line of parents snaking through a classroom on an overcrowded school tour. But in your quiet moments, you recognize that you have almost no objective criteria for choosing the right school for your child. Peg Tyre, a longtime education journalist, will be taking your questions this week. To start off, here are five tips for identifying what makes a "good" school for your young child.