I was just woundering, does blender let you sell pictures/renders you made from it? I was woundering that for a while now since most free programs you need to buy an agreement to sell. 
You have full control and ownership of your artwork, and you can do with it whatever you like.
You sure can.
The only thing that’s restricted is repackaging and distributing Blender itself (or the BlenderPlayer) without the sources (and I probably got part of that wrong too. All that GPL mombo jumbo…).
Anyway, images and animations you make from Blender are yours and yours alone. You can do whatever you want with them.
Martin