File formats

I was thinking about getting rid of some of my models at turbo squid how does one sell there stuff there? Also the file format seems to always be in .max, .3ds could I just resave my work under that. (plant.3ds or plant.max) or would there be other stuff that I would have to do?

I’d export (File / Export), as a more universal file format such as .obj which can use used in almost all 3d packages. Some exporters from blender are better than others so if you do export check it in another application before selling it to ensure it is saving it correctly with all maps applied correctly etc.

Right now I only use Blender is there any other free programs that I can use to check my work on?