When I hit "render" nothing appears except one object I forgot to add a material to. I'm unfamiliar with most of Blender's rendering settings. I've done some internet research but turned up largely nothing useful. I still have this problem. I've tried cycle's and the blender rendering engine. In fact this problem occurred when I switched from cycle's to blender...
For the record I am not willing to put my hard work up on here, but if you need information I can definitely post a screenshot of whatever it is that you need.
Some screenshots: