Choosing a School for Your Child

One of my good friends will be relocating to a new town soon. She has school aged children, so consequently, her children will be changing schools. She is wondering if we have any advice for researching and choosing good schools for our kids. If anybody has any tips or has been through this before, please comment and share!
Her question:
"What criteria should I look at with the schools when making a decision.  What do the different scores mean and what should I base the decision on.  Do you have any good websites that will help me understand the test scores and what they mean and what I should really look at when deciding?  Any help would be greatly appreciated!"