The Way We Work by David Macaulay (Houghton)
Over three-hundred pages explain how the human body looks inside and out. Large clearly detailed and labeled drawings make this an encyclopedia for readers from elementary through junior high.
Also watch for Macaulay's two volumes of The Way Things Work. As in the others, he shows the inner-workings of dozens of machines and electrical instruments. (I never knew what a carburetor in my car was or what it did until I looked at one in the first volume!) These are both wonderful gifts for "guys" who like to dabble with woodworking and electricity.