Russ Chappell's Marvel Chronology Project features chronological listings of practically every character in the Marvel Universe.   An excellent resource, a great group of folks on the boards, and I have to say I wouldn't have been able to even conceive of this site without it. 

http://www.chronologyproject.com/

Also on the Chronology Project is Paul Bourcier's Marvel Calendar, which is exactly what it sounds like: an attempt to chronicle Marvel Time on a Calendar of Events.  If that sounds familiar, it should.  Paul is the Father of the Calendar Method of chronology, something that really clicked with me when I was trying to figure this whole thing out.  Honestly, I have no idea how I would have pulled this together without it.  Also, check out Paul's Avengers Year-by-Year Timeline on the excellent Avengers Assemble! site. 

http://www.avengersassemble.us/

If you happen to be in Northern Illinois, swing by one of Amazing Fantasy Books & Comics fine locations.  Or, you could visit them on the web:

http://www.afbooks.com/

http://www.myspace.com/afbookscomics