Read the stickies, there is a good bit of important info that's covered. Get your doc to fill out an RFC form for you. The diagnosis is less important than many assume. The severity of your disability and how it impacts your ability to function is what you need to document. RSD is not one of the "listed impairments" but even having a diagnosis for one of them doesn't automatically mean approval as some assume. SS did a write up about RSD several years ago that you could provide to your case worker. I can't link at the moment--if you're unable to find it pm me for it.

About 1/3 of applicants are approved in the first stage. Do not take the process lightly... The rules have changed so that you can't start a 2nd application while in the appeals process--many of us took advantage of that--but it means tough choices have to be made if you aren't approved early on, now. You can end up with the long delays and no other recourse if you want to keep potential backpay. If you live in NY, NJ, CA, HI or RI, you'll have 1 year of state disability while waiting, which can make things easier.

I suggest getting a copy of the NOLO book on SSD.