As if you had to ask. In any case, here's the scandalous Vanity Fair article about the Pentagon cooking intelligence about 9/11. I'm impressed that the magazine went as far as it did. If only another high-profile publication would go as far as the rest of the national media didn't go. If you want to read the most damning, least controversial, easiest to confirm book on the subject, read Nafeez Ahmed's The War on Truth.
This book only scratches the surface, but it's the most important surface. Ahmed doesn't even deal with the obvious controlled demolition of the WTC; he mostly details who knew what when, based almost exclusively on worldwide journalistic sources. Frankly, that's all you need to conclude that elements of the US and other Western governments were complicit. Look at more of the details and it's far, far worse than you might think.
UPDATE: Four of the 9/11 widows that Ann Coulter hates so much are calling into question the entire 9/11 Commission and its report.