The techniques outlined in the Army Interrogation Manual prior to Bush taking office would be a good place to start.
Those techniques were considered good enough to protect us during a shooting conflict (and potential nuclear war) with the "Evil Empire" itself, after all. You know, things the government thought would protect us during a situation where the Commie tanks could overrun Europe and Russkie guided-missile subs could be in New York Harbor and Soviet bombers could fly right over Sarah Palin's house.
Somehow, I think that as dangerous as al-Qaeda might be now, their threat kind of pales in comparison to that.
Where in there does it specify no waterboarding?