Many times we are asked "How do I know what to teach in which grade?". Many curriculum's are set up to guide you to age/grade appropriate levels which is helpful. In Alabama you aren't required to teach a specific things in certain grade levels, and further, one of the great freedoms of homeschooling is the ability to move your child up and down per their abilities in each subject. It's very common for a child to be at one grade level in one subject, and another grade in another subject. The information given here is for you to get an idea, or to help you stay on a guided track if that is important to you.
World book is an easy to navigate site to help you find what to cover from preschool through grade 12. It covers Arts, health and safety, Lang Arts, Math, science, Social science, and technology.
This site answers several "what should I be teaching" questions for homeschoolers preschoolers through middle school. The links given here are very homeschool specific.
Scholastic School Success Guides are from Kindergarten to 8th grade. In addition to helpful guidelines this site also has fun books to go along with those guidelines!