Hi W.,
I researched this very question when moving here from Arkansas. I'd suggest you make a list of a few questions you find important and then research the answers for several schools, ranking the answers if possible.
If academic performances are important, look at the TAKS scores which are available online at http://www.tea.state.tx.us/student.assessment/reporting/
This site has a great deal of helpful reports.
If ethnic diversity or average household income is important, look at that, too. If, for example, you value your child growing up in an ethnically diverse environment in school or don't want your child overly influenced by a high percentage of wealthy fellow students, researching this now can help you choose a good fit for you and your child.
Feel free to contact me with any questions,
J. B
Parent Coach