We use Apologia Science books for school. I really like how they focus on only one subject for the year. I also like that it is a conversational textbook. I use the book by reading a small subtitle each day. Then, the child does a small activity that relates to what we discussed. I would estimate that each chapter in the Apologia book has about 4 to 6 notebook pages which correspond to each chapter. It takes us no more than 15 minutes unless we are doing an experiment. I also occassionally blog about their experiments. Often, I just make a copy of what I wrote from the blog and have them place it in their notebook. Here is a small sample of the Little Lady's Botany book from this year so far.
Specifically Bee Pollination and Bee Vision in regards to seeing pollen
Bess don't see red they see more the ultra violet colors.
Seeds - Self Pollination Food in which we eat.
You can view more underneath the label "unit: botany".