There are several websites that offer lesson plans in curricula for the age and grade that you will need. Some of these websites are free and you can print out the lesson plans and several other documents. Homeschoolcentral.com offers curriculum for pre-school through high school. They also offer study resources for all subjects. Brigham Young's website (ce.byu.edy) also offers courses through its website for middle school and high school age. Most involve a fee but there are a few free courses.
Check your state's website for information and requirements for home-schooling. They will also have links to other websites that offer exact curricula that the student will need. These usually contain text books, CDs for the computer, and website links that will help to home school the student. New Mexico's education website, for example,lists all of the requirements needed to be able to homeschool a student and also contact information for those who have questions. Colorado's site also lists academic standards for each subject and each grade.
Curriculum workbooks can be purchased at teacher resource stores, such as Teacher Heaven and Mardel, and at many bookstores. Teacher resource stores are retail stores that sell teaching resources such as printables, charts and posters. Most offer curriculum workbooks for each grade.
There are homeschool groups that get together to help each other out. In larger cities, they offer sports and other extracurricular activities for homeschool students. These groups are also a support group and resource for questions that you may have. They give the students the social aspect that a public or private school would offer. Home School World (www.home-school.com) is a resource for local groups and activities. They have listings for each state with different groups and their contact information. It also gives a brief summary of what the group is about.