Launching a contest....Suggestions? Contest Burner?

I am thinking of launching a contest for one of my websites. What is a good way to go about this? I read about Contest Burner, and it looks good, but I am always a bit leery of those long sales pages!

I just want a system where people can post a story or something, and then get extra bonus entries for launching it on Facebook or Tweeting it or something…

And it would be nice if each entry was a page indexable by SE’s!