There are two great things high school students can do to prepare for college over Christmas break: shadow a professional and apply for outside scholarships.
For freshman through seniors, job shadowing is a great way to explore career options in an area of interest. Connect with someone in your church or a family friend and ask if you can follow them for a few hours and interview them about what they do.
Also consider applying for outside scholarships. Students who spend the extra time to apply for scholarships can get thousands of dollars in money toward college that they never have to pay back, in addition to what is provided by their school of choice. Here are a few great sites to get you started: