AP classes, world languages. you should also be able to find ACT/SAT scores, dollars per student, etc. if you're interested in all of that.
Whoa! All of that will change by the time it's needed!
Don't drive yourself crazy with this. Find a good kindergarten and elementary and don't stress about later.
Boundaries change, admin changes, schools switch from AP to IB, budgets change, etc.
The school I teach in doesn't meet AYP, but it's still on the best schools in the US list. I don't really get it. Grade inflation? Large course offering? Who knows.
In the end, I think it comes down to the parents: read to your kids, take them to museums, do fun science stuff with them, etc. no matter how good a school is, if kids don't get enrichment activities at home, they lose out on the biggest boost. Anything you can do to keep a kid's curiosity going is good. By the time I get kids in high school, so many have no curiosity or interest in anything. Half my kids were super uninformed about space and NASA and had never been to the air and space museum (it's free and fun and 30 minutes away!)
You can pull up school report cards from the dept of education site for your state. These list things like crime and discipline problems as well as test scores and how they compare to the state average.
I teach in a ginormous school. Most of the kids still seem to know each there because they end up in the same classes. They get a much broader choice of electives, languages, AP, etc.