Consult with the colleges you are interested in to see if they accept AP credits, and with your high school to see which AP courses are offered and how to sign up. You have to be a little crazy to try this, but motivated students can possibly complete a four-year education in three years. A more reasonable goal might be to reduce time in college by half a year. Even at half a year, this strategy may take its toll on the student. Academics are only one part of the college experience, and by accelerating the process, a student may lose out on some of the opportunities and friendships that make the college years meaningful.
Many schools allow students to defer admission for a year.
If your family is financially strapped, use this year to earn money. However, if the college the student really wishes to attend decides the family is not eligible for aid and the family cannot shoulder the entire cost of college, this might be the only way the student could make up the difference. Be extremely careful in making a decision like this. If there is no reasonable plan for how you can meet the entire four years' worth of college bills, it may not make sense to begin the first year. Some schools allow students to attend college part-time so that they can earn money while they are in school.