While the federal government does make some decisions regarding education, the 10th Amendment of the Constitution provides that individual states must control their own private and public education systems. This includes homeschooling. States therefore set their own requirements and regulations regarding families who wish to home-school their children.
Some states do not require the parent to contact an educational authority at all; some require high levels of regulation and monitoring; and others fall somewhere in between. The state regulations you must meet probably fall under the jurisdiction of the state you are living in, even if you are a legal resident of another state.
Contact your state's Department of Education for materials, regulations and resources regarding homeschooling in your state. Every state has a legal requirement for homeschooling families, even if that means you aren't required to notify the state about your homeschooling intentions at all. Once you've gathered materials, contact a local or state homeschooling group with an established record in your state to help you sort through some of the laws and regulations. Groups that have a large number of members, a long history or an active homeschooling community are the best to contact.
Not keeping required records, submitting test scores, meeting minimum educational requirements for parents or not contacting state officials with your intent to home-school can all be violations of the law -- depending on the state you live in -- and can complicate your homeschooling future. Follow state regulations closely and get any required paperwork handed in on time.