Does homeschool curriculum include everything I need for every subject?

Not always!  Make certain you know what is included in your curriculum!  Many families use one company for math, one for language, one for science, etc.  Sometimes a curriculum requires you to purchase supplemental books.  Some companies do offer packages with complete curriculum designed for each grade level, while also allowing you to purchase each subject individually (enabling you to customize your curriculum for your child).  There are also some companies who offer “DVD” or online classroom instruction, complete with grading and testing of the materials.