In each volume of MAKE we have "major projects" these project pages are meaty step-by-step articles with start-to-finish photos, precise instructions and how-to learning that can range from making a VCR cat feeder to ariel kite photography. In MAKE volume 07 the projects are:
Two BEAMbots: Trimet and Solarroller by Gareth Branwyn. Solder together one simple circuit and use it to control two very different solar-powered robo-critters: a little satellite that scoots and bumps around, and a mini cart that just keeps a-rolling until the sun goes down.
http://blog.makezine.com/archive/2008/07/make_projects_volume_06_1.html