Let's Try it Out Towers and Bridges and Let's Try it Out in the Air are great little science lessons perfect for young children. These books are designed to be used in a classroom setting, but it was easy to adapt to an at home thing. It's written in a story book format with a new idea to try covered on each page spread.
We have checked out both the water one and the one on Towers and bridges. Moira definitely liked the water activities better, and it while it already covered stuff she already knew about water displacement and density, it was a great way to explain more about the scientific process to her. For instance, the first activity was to guess how many cups of water it would take to fill up the sink, so we had to both figure how full we wanted to make it and a way to remember what that point was, and how full we wanted the cups to be and how to tell when we had reached that point. The strange way she's holding her hand was her solution, and she assigned me the task of holding my hand in the same spot on the sink.
Moira was less interested in the towers and bridges books, even though it was actually new information to her. Actually she really liked the beginning where were working with straws and playdough to make towers, and then blocks and paper to make bridges, but I think the ending where we were supposed to combine all of the techniques to build a strong house was a little beyond her. She's never been much of a building kid, and the first couple of activities really stretched her abilities. I suspect that a kid who loves building would have gotten a lot more out of this book.
Science Play series by Vicki Cobb. Pictured here is I Face The Wind. There are four books in the series and I think we have them all. I promise we have read them and done the activities it was just long enough ago that I can't find the pictures right now. The activities in these books are a little less linearly connected, which is great because you can concentrate on one or two at a time easier. There is also a little bit more explanation about why things are happening.
What science books have your young children enjoyed?