I've posted a bit on 'when to go on disability' from my doctor up in the other forums because there had been a discussion about it. I was looking for information on when (and how) to tell work when I ran accross this site. Despite the fact the guy is a consultant, there's a lot of free info on his site, just check out the links at the bottom of the article. I found it VERY helpful. It includes tips on what to do while filing, etc.
http://www.helpwithbenefits.com/Articles/HowCanAConsultantHelp.htm
http://www.helpwithbenefits.com/Articles/HowCanAConsultantHelp.htm