I'm not a big fan of buying lesson plan books, but I came across these planning / record-keeping pages for high school that I downloaded.  After looking through them, I will actually use these.  It will give me an easy way to keep more details of what we are doing instead of just my excel file that I have used up to this point.  You can use these forms ahead of time to plan out your schooling . . . or use them to write down what was done to keep track of the many things a high school student does that can fit into a subject for their transcript.  These pages will work great for a variety of homeschooling styles -- from traditional schooling to very relaxed schooling.  They are usually $10 but are free this week only.  (In my opinion, it's probably worth the $10 if you miss it during the free week).