I have an NPC that can use:

magic
bow
2H weapon
1H weapon
1H weapon + shield


...but I cannot figure out how to make an NPC fight using 2 weapons. He has 2 weapons but he's just using one. I gave him the Thalmor_dualwield AI package but no luck. I'm a total newbie to CK so any help would be appreciated... thanks!

Dual wielding is controlled by the http://www.creationkit.com/Combat_Style. You have to give the NPC a style that supports it.