Pixar, the company behind Toy Story, Cars and other incredible animated movies, has announced that it's in-house 3D rendering software, RenderMan, is now free for non-commercial use.
RenderMan creates the rendering with lighting effects. It does not create the original 3D model. You would need to first create the 3D model first. Maya is a great 3D modeling program that has a free version for students and teachers.
This is a great tool to help students learn graphic design and create some great projects.