For those who have used this, how long is a typical lesson? Do you follow their schedule or do a longer science day?
The program is super flexible. It is divided into units vs lessons. There are 12 units. At the bare minimum, you could read the "for my notebook" page and then do a lab or two. On the other end of the spectrum, you could find all the books on the book list, do all the labs, and then do some from suggested activity books.
We did the "middle of the road" approach. For us, I would find out which books our library had and place them on hold. Then, we would read the books over the course of a week or two (two if my dd loved that topic) and sprinkle the labs in. We did most the labs in the book. We only did a few that were found in outside books.
The "suggested weekly schedule" has you work on the program twice a week. We tended to go in spurts. With the exception of the unit on the planets, we did most activities and read on average 3 books per topic. We frequently reread the books because dd was interested enough to really want to "know" it. For us, the planets were less interesting so we skipped learning about each of them individually (in depth) and focused more on the solar system as a whole.
I bet we averaged about an hour a week. I hope that helps.