Contact your local state government office or school board to find out if your state has specific record requirements. Many states have laws that dictate how parents need to keep track of their children's homeschooling.
Acquire any previous records your child may have from schools already attended. These serve as a baseline for assessing your child's level of education.
Create a course curriculum for every topic studied and plan these curricula a year in advance. Mark your student's attendance (dates he attended class) as well as some record of his performance on each topic. Store these documents in a safe place at the end of the year.
Store all immunization records, progress reports and dated homework in a file with your course curricula.
Keep a daily journal of what days you taught, what was taught on those days and any issues that arose during the course of the day. The more detailed your records are, the better.
Be consistent. If you are following your state guidelines, the exact method and manner of your record keeping is not important as long as you are consistent in getting it done.