Many colleges ask for two or three letters of recommendation when you apply. Consider people who know your talents well—teachers, mentors, employers, coaches—then think about who will write the strongest recommendation. Make sure to politely request these letters at least two months ahead of your application date, and include all the materials they’ll need to submit your recommendation directly to the college.
You may want to ask people who can talk about different aspects of your achievement (academic, athletic, character), or you might want to focus on getting recommendations from those who specialize in your intended course of study. Some colleges will ask for specific types of recommendations (e.g., a character recommendation in addition to academic ones), so make sure you check requirements in advance. Talking to your guidance counselor may be helpful in choosing whom to ask.