I've been working on a series of short Tinkercad tutorials, for my students and teacher training workhops. Tinkercad is a full-fledged primitive modeler that works in any WebGL enabled browser. It's simple, easy to use, and I'm loving it because it generates STL files for 3D printing that are generally error-free (and anyone who works with 3D printers know how important it is to have correct meshes to print). This first series is about Tinkercad's user interface, tools and workflow:
Have fun! And Tinkercad also generates VRML files ;) ... so, enjoy!