Xavier's School
Located outside Salem Center in Westchester County, New York, Xavier's School for Gifted Youngsters is publicly known as a prestigious boarding school, providing an outstanding college preparatory education to middle- and high-school students. With a rigorous academic curriculum and a low student-to-teacher ratio, Xavier's sends students on to the best colleges in the country.
While Xavier's does provide its students with an excellent traditional education, its true purpose is hidden from the public. Founded by its current headmaster, Charles Xavier, in his family's ancestral home, the school serves as a safe haven and training ground for young mutants to learn to cope with and control their powers. Alongside more typical high school classes, Xavier's students receive instruction and guidance from the faculty in responsible use of powers and the ethics of living with them.
X-Men
Also founded by Professor Xavier from the ranks of his most promising first students, the X-Men take a still more proactive role in furthering Xavier's vision of peaceful mutant-human relations. Whereas the school does this by teaching young mutants to use their gifts safely and ethically, the X-Men do this by working to protect the world, even those parts of it that hate and fear them. A team of highly-trained mutants, the X-Men work both to combat persecution of innocent mutants by humans, and also to combat mutants who use their powers in hostile and destructive ways. Many but not all of the teachers at Xavier's are part of the team, though it also includes others -- former Xavier's graduates, or mutants who have allied themselves with the school. An open secret among the student population at the school, students are not allowed to join the ranks of the team until graduation, though many of the more promising students are offered extra training if they seem like good fits for eventual membership.
For those who live and/or work at the school ICly, the following pages provide useful information that your character would be familiar with.