I teach high school and have used a Moleskine Academic Weekly Notebook for each of the past three years. I use the left side, which features the week divided up into six horizontal sections, with Saturday/Sunday sharing one space divided vertically, to track assignments, lesson planning, meetings, etc. I use the right side, which is a ruled notebook page, to write down ideas, notes for lessons, and anything else that comes to mind for that week.
At the end of its period of usefulness my Weekly Notebook is well-worn; each page is more or less filled. The Notebook is now a permanent record of my organization and planning for that academic year and rests labeled on a shelf in my classroom.