If you want to learn more about provable facts of 9/11 I suggest you check out the documentary film The Truth and Lies of 9-11 by Michael Ruppert. You can find the 2004 update version DVD on most of the
.torrent sites or the original on
Google Video. It is by far the best 9/11 documentary due to the credibility of Michael Ruppert, the way the facts are methodically presented and that Mr. Ruppert focuses on facts that can be documented and proven and not making wild conclusions that are more opinion and what if's than documentable facts.
When you bring up 9/11 films most people (especially those younger than than 30) will cite Loose Change 2nd edition as THE film to watch. While I agree it has some valid points (regarding to the WTC 1, 2, 7 collapses) it is full of disinfo and unproven conclusions when it covers the pentagon and flight 93.
If you are still skeptical of government involvement the films Truth and Lies of 9/11 and Michael Rupports newer film Denial Stops Here which is more of a compilation of newer footage from his speaking engagements from 2001 - 2005.