The first link is to the official Oktoberfest site. Lots of good information. Be sure to check out the FAQ section to see a calendar for the next six (6) years and the answer to the why Sept. question.
The second link is to a BeerAdvocate article that does a nice job summarizing the history of the event.
I've been trying to get my hands on as much Oktoberfest and as much Pumpkin Ale as possible. Two (2) Oktoberfests worth mentioning (I don't have time to do a full review, so just a few comments will have to suffice):
- Once again, Sam Adams Oktoberfest is a solid beer. However, it seems to me that the best Sam Adams O'fest was about 3-4 years ago. Although I enjoy it and look forward to it every year, it's never been as good since.
- Summit's Oktoberfest was a lot stronger than I had expected. Lots of great tastes--a nice, chewy malty flavor. I think the high alcohol was a little out of balance though, because it came off kind of harsh.