Original post by: Kyle ,
Google Sketchup and Blender are free options available for download online. Autodesk also has free licenses for students and faculty that you may be able to access, as well. SolidWorks and Rhino are also two other programs that can be used, but usually must be purchased. For electronic sketches, I'm less familiar with the available options, but I'm sure there are some free options online. Hope one of these programs solves your problem!