Apologia is our go to Science curriculum for elementary. (We are in the elementary stage still, but they do have Jr/Sr. High books too!) I like them for a few reason. The main being its Christian based. The lessons are very well laid out and can be split up a few different ways, if you so choose.
We have started meeting once a week with another family to cover a chapter of the book. We read the lesson, ask the questions and have the kids write/draw something they learned throughout the lesson. We will then do an experiment or two, time permitting. There are sometimes little things in the middle of the reading to do, otherwise they are at the end.
You can buy the additional notebooking journals (which we did) or make up your own. The Apologia journals are spiral bound and come with a lot of extras. There are mini books, vocabulary puzzles, copy work and coloring pictures, to name a few. They come in regular and junior. I would definitely recommend Jr for 1st-3rd. 3rd graders could really go with either bock and 4th on up should use the regular journal. The Jr. journals do have the coloring page (which my 5th grade LOVES), and the kids color while they listen to us read. They could very easily draw their own pictures (space is available for that) or you could find and print one for them to color and paste into the book.
Our plan of attack using these books...
Astronomy (almost finished)
Zoology 1 - Flying Creatures of the 5th Day
Zoology 2 - Swimming Creatures of the 5th Day
Zoology 3 - Land Animals of the 6th Day
Human Body (probably here, but maybe after Botany since it will fit with CC Science schedule)
Chemistry and Physics
The books average about 15 chapters. There is a "Lab List" in each, broken down by lesson so you know what supplies to have and when for the experiments. For Zoology there are flashcards you can download and print (but we aren't there yet).
Classical Conversations Science
The kiddos also do a science experiment or two each week at CC. (Which takes some of the pressure of if we don't get to the experiments and projects for Apologia.) In addition to experiments, they have their weekly memorization, which will serve them (and me) well when we hit that area in our curriculum. Those memorization "pegs" I tell ya....pretty amazing!!!