Most wanted SAT and ACT scores. They wanted the student to have had some control over the curriculum. They also wanted some proof that the student could work outside the home, such as part-timing or taking college classes at a local junior college. Some wanted a portfolio of sample work, but most didn't. They all said they had accepted at least 5 homeschoolers a year, and Stanford even says they give homeschoolers a slight preference because they have more interesting curriculums, self-directed learning skills and outstanding social skills.
Many colleges now list special entrance requirements for homeschoolers on their web pages.
It's important to plan well ahead to be sure you know what the schools want you to have studied and what they will require. Used under License.