It is best to check with your state's Department of Education to find out your legal obligations. Each state has its own rules, although there are some common themes among them. In general, you are required to send an annual notice to update your local school district, which includes basic information about your child and your child's academic progress. It is also likely that you will be required to follow curriculum guidelines and to record your child's attendance.
Record keeping is important for the administrative side of home schooling. You'll need to record your child's attendance, since all states mandate a minimum number of days' attendance per year, even if your child is home-schooled. You should also set up regular tests and other assignments. Not only do some states require you to submit academic records for your home-schooled child, but creating and grading tests, as well as offering regular assignments, are reliable ways to measure your child's academic progress.
If your state has curriculum guidelines for home-schooled children, then you should use those as the most important components in building your curriculum. Some states post their curricula online, which you can look at and draw inspiration from, if that is your desire. You can also find a wide range of already completed curricula for home-schooled children and other resources online. Simply enter "home schooling curriculum" followed by your state into any search engine to bring up a list of the relevant resources. Some of these resources are free, while others must be paid for.
Be sure to institute a daily routine for your child, since a routine will help build discipline and make it easier to get through each day. Set break times between study sessions to help prevent your child's attention from wandering and to keep your child focused on the lessons. Similarly, take care not to neglect your child's social education. Take your child out on extracurricular activities; see if you can find a local support group for other home-schooled children from your school district, your community, through the newspapers, the Dept. of Education or online.