I think I speak for a lot of people when I say a nice, simple newbie guide on how construct an app that connects and gathers information from a MySQL database (with PHP) on an outside website would be an excellent resource for the people that have never used OAuth or OpenSocial before, or JSON for that matter.
I'm faily decent with Javascript, PHP, and MySQL, but the platform is still giving me nightmares on how to connect between sites and deliver information securely. An example with the complete files involved would be excellent. Perhaps the person up for the task could provide a donate link, or even sell the information. Personally, I would pay to receive this info ($25-$50), as it would save a lot of time sifting through the documentation that makes no sense to a large share of interested developers without an application background using opensocial or oauth.
If anyone would consider it, I'd be happy to share my views of what I don't and do understand about the platform from reading the documentation thus far. I can't stress how important the complete files needed are - it delivers a total understanding of how everything works together, without having to guess.