The al Qaeda manual

Citizen Warrior - A significant purpose of fundamentalist Muslims is to try to establish Islamic states everywhere in the world until the whole world is Islamic. Organizations like al Qaeda are working hard to do just that. (...) Part of the strategy is to undermine trust in a government's ability to protect its citizens by committing dramatic acts of terror. But to do this, a terrorist needs to blend in to the foreign society until the appointed hour of destruction. (...) Because Islamists exploit a moral principle in western democracies, they are actually gaining ground on what would seem to be an impossible goal. (...)

Tactics for concealing one's true identity in the land of the infidels. (...) Measures that should be taken by the Undercover Member:

Have a general appearance that does not indicate Islamic orientation, avoid visiting famous Islamic places (mosques, libraries, Islamic fairs, etc.), not resort to utilizing letters and messengers except in an emergency, not speak loudly, not contacting the overt members except when necessary. Such contacts should be brief. More...

Full manual