need help getting started with any of the autodesk or adobe creative cloud applications? check out the tutorials on linkedin learning , formerly lynda.com.
mattercontrol - aside from being a 3d slicing software, mattercontrol lets you make 3d designs from 2d images (photos, drawings, etc.) we've also used it to make 3d stencils from hand sketches.
touchterrain - lets you create 3d models of topographic data (primarily u.s. data). exports models as .stl files so they can be 3d printed.