SketchUp is downloadable 3D design software and webware used by teachers and students to create models of anything they can imagine – from toys to buildings to theater sets or cars. SketchUp can also be used for computer-aided design (CAD) or geographic information system (GIS) applications by itself, or in conjunction with Google Earth.
The free products include SketchUpMake for download to your computer; my.SketchUp, the online version; and 3D Warehouse, a large collection of components and models you can add and modify in your Sketchup creations. There are also SketchUp model viewers available for iPad/iPhone and Android devices.
Be sure to watch the video tutorials to guide you as you learn how to use the tools. Another useful resources is 3DVinci.net, which has a free SketchUp Guide for Teachers. The video below is an excellent discussion of how teachers are using SketchUp in the classroom, and additional resources for teachers.