When you have finished the Considering God's Creation manual, you may want to try 175 Science Experiments. While Considering mainly concentrates on earth and life science, 175 Science Experiments focuses on physical science.
I stumbled across 175 Science Experiments a number of years ago at my public library, fell in love with it, and bought my own copy. Although it comes from a secular publisher, I didn't find anything in it that should be objectionable to Christians--no evolution or other nonbiblical worldview stuff (and I am really a fuss-budget about this). Subjects covered are Water, Air, Movement and Light.
This is a full color, lots-of-pictures book, with simple experiments that work. No spending hours setting up an experiment, and then whatever is supposed to happen never does. Many experiments have a "How it Works" paragraph at the end to let us know what should have happened, and what we have learned. The ones that don't are so self explanatory that even the most scientifically challenged among us don't need any further expounding upon what we have done. I need this kind of simplicity!
175 Science Experiments is probably written for kids in the mid to upper elementary grades. I must confess, however, that we used this book as our only science curriculum during 7th and 8th grade--and gained mountains of science knowledge by doing so.
The sequel to 175 Science Experiments--175 More Science Experiments--covers Sound, Electricity, Chemistry, and Weather. I have not personally used this book. It has a different author than the first book, which sometimes means a significant difference in style and quality, although it is likely that the publisher tried to keep things uniform.
(This review was written Summer of 2002 and updated Spring of 2008.)