Not everyone thinks this way, but I am a whole-to-parts kind of thinker. I use an organizing principle to begin, plan and end. In my mind the tool looks like a wrapped piece of candy. So, I start with an organizing principle to begin my planning, stuff all the details in as I go on planning, and end the year finishing up with the same organizing principle.
And this magical tool is -- a transcript. I KNOW, I KNOW, I KNOW -- that's the scary part at the end of high school for most homeschool moms. Just hang with me. It's just a piece of paper. (Mine is an excel document, but you can do it in Word or just on a piece of paper.)
If you need to meet your state's requirements for graduation, this is where you take it into account.
First, take your blank piece of paper and put down categories that you want your student to learn. And put at least 4 lines between each:
Next, fill in what you know. Do you know what math curriculum you'll use? (We're Math-U-See fans, here.) Even if you're unsure if your child will make it to Calculus in his 4th year, fill in what you'd like his high school to look like. It's just a piece of paper.
You'll obviously have some blank spaces. Do your best to fill them in. Don't know what English curriculum you'll use? Call it English 1, English 2, English 3, & English 4. Even if you don't know what x-curricular classes your child will take? Guess. Might he like photography? You have 4 years to make it accurate, for now just fill it in with your best guess. When you're relatively sure about something, highlight it. Then do a happy dance. When you get a chance, move onto the next thing you're close to figuring it out.
Now, when you've filled it all out, you have a 4-year tentative plan.
Next, you're ready to buy some books and start lesson planning. (This is the start of the candy part.)
My finalized lesson plans look like this. The kids get a printed copy in glued into their student planner and I glue a copy for me for each child into my teacher planner. Then as the year progresses, I track grades on it and where we are in each subject compared to where my plan thought we should be (because those things NEVER match up).
Then at the end of the year, I update my transcript for what actually occurred through the year, adding class descriptions and a books read list (organized by class). I also use my transcript to begin planning for next year.