Locate a list or collection of the best music schools in the country (see Resources). This will provide you a list of schools to start researching and possibly choose from. Either print the list or quickly jot down the names of the schools.
Visit the website of each school and look for information regarding their programs, degrees, areas of study, cost, admission policies and audition guidelines. A good place to start is the school's "FAQs" or "Q and A" section, if available. Use this information to eliminate the schools you're sure you don't want to go to while also making note of any that spark your interest, moving them to the top of your list.
Research the placement of graduates and how many get hired after finishing their education. If certain organizations frequently hire graduates from specific schools, contact their Human Resources department and ask why they value graduates from that school so much. Get in touch with graduates to get first-hand accounts of their experience and education. If you can't find anyone to talk to in person, try the Internet and social networking websites.
Visit any of the schools on your list that you can. While it may be too expensive to visit them all, visiting the schools closest to your home or the few you like most will give you a much better understanding of the school and atmosphere than the website does. If possible, sit in on classes and note how the professor and students interact. Do the students seem to be learning, and is the professor teaching clearly?
Compare your top choices by using the knowledge you've gained researching the schools. Instead of choosing a "best one," consider applying to multiple music schools high on your list in case you don't get accepted into your first choice.