Third Anniversary. Please read "The Coincidence Theorist's Guide to 9/11" at Jeff Wells's Rigorous Intuition blog.
This past Thursday, I attended "The Omission Hearings" a day-long event held in Manhattan by the 9/11 Citizens' Commission. A list of people who spoke is here. One aspect of the disaster that I have done very little reading on is the environmental impact of the buildings' collapse, so the testimony of Jenna Orkin, co-founder of the World Trade Center Environmental Organization, was nothing short of mind-blowing.
There are dozens of books out there about 9/11 and its myriad tangents and there will be dozens more. But for the average person, there is perhaps no better source for 9/11 information that Paul Thompson's "The Terror Timeline" (and I would say that even if I hadn't written some of the book's entries and co-written an article with the author). All of the information in the book (and more (plus links to the thousands of news articles cited)) can be found here. ... The book could fairly accurately be subtitled "Everything You Know About 9/11 Is Wrong."
I should also point out the existence of the 9/11 Omissions Dossier -- which will point out all the contradictions, distortions and outright lies in the farcical report issued by the 9/11 Commission.