ScientificAmerican.com and SolarCooker-at-CantinaWest.com are two sites that feature instructions on how to build solar ovens. SolarCooker-at-CantinaWest.com also offers links to a number of other sites that feature plans for different types of solar ovens, including parabolic solar cookers, box solar ovens and solar panel cookers.
Scientific American's instructions to build a solar oven, which are aimed at children, utilize an old pizza delivery box, some aluminum foil, plastic wrap and black paper. The instructions offered by Solar Cooker at CantinaWest are aimed at adults and utilize materials readily available at a local hardware store, including a roll of reflective bubble insulation, a canning jar and an oven roasting bag. Links to a range of sites offering instructions for alternative home-built solar ovens are located in Build A Solar Oven under the Build Your Own tab on the SolarCooker-at-CantinaWest.com home page.