Any good examples of a design doc?

Hey I am not sure if this is the proper forum to post this question so I apologize in advance if you have to move it =)

I have been working on a design document for a small game I am trying to make (just myself and hopefully a couple more people if I can find them). Anyway, I am getting writers block because I have never done this before. I have a good rough example of a *blank* design document showing what the structure should be like and whatnot, but I am having trouble adapting that to my game. I am still not quite sure what to write about and where in some places.

If anyone knows a place where I can find/download/obtain a full fledged completed game design document, either for a game thats maybe been out a very long time or one that was never made (nothing fancy in other words), please let me know!

Thanks guys!