Evanston High School has had a long tradition of excellence. I did my student teaching there many years ago and I have friends whose children have graduated from there in the past 15 years, all with positive experiences. Like most high schools, it is home to all kinds of students. Demographically, it is more diverse than many of its neighboring schools--like New Trier, the Glenbrooks, etc. For specific information about the safety of the school's location, I would suggest that you call the Evanston Police Department to ask about recent crime statistics in that particular neighborhood. You could also check with the high school itself for specific reports of incidents that have occurred in the building within the past year.
Good luck and please let me know if I can help you find a home. I have lived, worked and raised a family on the North Shore and am very familiar with its many villages.