K.W.
Check out www.greatschools.net. This may get you started in your search for a private school. Some listings even have parent reviews about the school. I can totally understand your concerns, as my son will also be entering Kindergarten in the fall. Fortunately, the public school he is attending is a good one (I've done the research and personally visited the school, which is what I'm sure you'll want to do too.) Just remember that a huge part of any child's success in school is the parental involvement. You are obviously a caring mom who has a vested interest in the future of your son. That alone will help to keep him on the right track.
Safety is a concern of every loving parent. We can't be with our children every minute of every day; my suggestion to you regarding this issue is simple- do what you can to provide a safe environment for your child and leave the rest to God! Pray for his safety and overall well-being! Yes, it's sad and a little scary to know that there are so many sex-offenders in your neighborhood, but at least you KNOW who they are and where they live. Lots of children are around sex offenders everyday and we don't know it and that's even scarier, in my opinion. Good luck and know that you are not alone in your concerns!