How can I import 3D models created in Autodesk and Tinker cad into Blender 2.69? What file format should they be saved in?
Welcome to Blender SE!
Which Autodesk product are you using?
This documentation talks about what file types Blender can import. Depending on what Autodesk product you're using, Blender might be able to just open the file that it uses. OBJ is usually the most widely supported, but materials can be difficult and it doesn't support any proprietary features: OBJ will only export the mesh and sometimes materials (no shapes, no rigs, no animations, etc).
I can't tell for sure, but I'd be willing to wager than Tinker supports exporting OBJ files.
If all you want is the model, OBJ is your best bet. In which case:
- Export your original file as an OBJ
- Open Blender and File -> Import... your OBJ into a new scene, or a scene you've already started.