Another excellent multiplayer community video was recently released, What's role-playing and how to do it? by Larpushka. It introduces roleplaying concepts and a helpful overview of some of the types of experiences available in the NWN MP community. It is also a nice complement to the NWC Quick and Dirty MP Roleplay Reference for newer players, which provides an orientation to the multiplayer interface and concepts such as emotes.
This has been added to the video links in the NWN:EE Multiplayer Resource page.