The first link is to a brief but provocative timeline of September 11, 2001. Events leading up to, and coverup afterwards. There are lots of smoking guns here, and it just scratches the surface:
This second link leads to a page of articles concerning various points raised in the first timeline. Again, events before, during and after the attacks:
Type 'Porter Goss' in the search engine and click on result # 5. That should lead you to an interesting account. Goss and Graham were the heads of the intelligence committees that would be investigating Sept. 11. Look at what they were doing the day of the attacks.
It is endless. This was a crime committed in plain view.