The NWC Multiplayer Connection and Hosting Guide is a step-by-step explanation of how to use NWN:EE in multiplayer mode. It walks through the process of both joining internet games and how to host one on your own computer. (Now updated to version 1.1 with additional info on server options and creating the DM client shortcut)
The new NWC Quick and Dirty Multiplayer Roleplay Reference is now available as a player aid. It should be helpful for those new to the MP experience, as well as serving as an (optional) reference point for common in-game behavior standards.
The site is also pleased to host two legendary Old School NWC guides, which still hold up very well for today's NWN:EE experience. The original authors gave their blessings for them to be hosted here.
-- Gruush's The Role Player's Guide to Multiplayer Neverwinter Nights
-- Lazybones' The Neverwinter Connections Community Guide to Dungeon Mastering.
All of the above, plus additional community resource links, can be found on the NWN:EE Multiplayer Resource Page.