There are many things to consider when choosing to home school a high school student including choosing the appropriate curriculum, choosing knowledgeable tutors or instructors and preparing your child for university.
Luckily, many universities and colleges have programs to help with this preparation.
Our local community college allows high school age students to enroll in classes through concurrent enrollment. Students are required to have a grade point average (GPA) of 2.5 of higher, basically a B- or better, and be in 11th grade. Students are not allowed to take a full course load because the courses should be in addition to other high school level coursework being completed. This has proven to be a wonderful opportunity for high school home school students to get a taste of college level work and earn credits toward university completion.
Another opportunity universities offer home school high school students are outreach programs. For example, Thomas University offers a Home-school Connections Program (http://moultrieobserver.com/local/x1236702451/Thomas-University-announces-Home-school-Connections-Program). The program offers free concerts, events and exhibits to all age groups and specifically invites high school students to join their book club and creative writing club. High school students, as well as community members, are invited to attend free lectures given by scientists weekly.
Finally, home school students are invited to use the university library and its resources.
I can imagine that one challenge for parents who choose home schooling for their high school age children is being able to provide a rich and diverse experience. Luckily, local colleges and universities are now welcoming home school students to join their activities and are providing parents with one more option.