One option that some states require of homeschoolers is that their children be under an "umbrella" program. Umbrella organizations are state-accredited and provide documentation and class options for homeschool parents to show that their children are receiving a full-educational course of study. Some umbrella schools supply books, worksheets and lesson plans. Others merely supervise what you are teaching, review it and document that you are teaching appropriate materials for use by the parent's local school district.
Some states have fewer requirements for homeschooling and so parents are freer to choose curriculum. There are hundreds of prepackaged curriculums available for homeschoolers. The curriculums cover grades from preschool through high school. Other options include secular or non-secular focused curriculums.
Some private companies and state-education departments design a full curriculum and make it available online for a fee. These sites track assignments and grade tests. Some courses within the programs make the problems harder or easier depending on the student's answers. This is helpful for children who may need more or less practice in a particular area.
Homeschool cooperatives, or co-ops, are groups of parents who join together in to provide educational and social opportunities for their children. Some parents volunteer to teach a particular class while the other parents pay a fee for the materials and location. Parents can pool a set amount of money and use that to hire a private teacher or tutor to teach classes.
Several national homeschool groups provide information about homeschooling in a particular state and the requirements. If a company says it is accredited, it is still a good idea to call the agency that accredited the group and verify that they are members in good standing.