The development team for Edon Drow Wars has modified a number of the existing base classes, added a number of classes from NWN2, the PRC expansion pack and also created some classes from scratch specifically for the module. Information on the base classes can be obtained via the links in this article to the NWN Wiki site, while info on changed and new classes can be found here.
The wiki is being updated with all the information that used to be found on numerous posts on the forums but as anything it does take some time to transfer everything over. If you are unable to find what you are looking for, then perhaps this link may help http://games.on.net/forums/viewtopic.php?f=69&t=23585&p=1540839#p1540839