A little more info on exactly what you're after would help.
Are you already comfortable in the creation of models, textures, etc with blender?
Are you looking for help or assistance on the process of bringing models from the game into blender? To expand on that, editing PLT texture files or the other incredibly niche and archaic file formats NWN seems to use.
I've recently forced myself through learning the toolset, being able to open / modify the file formats etc, so if you get hung up somewhere hit me up on discord and I'll be happy to help.
Some basic things you'll absolutely need that I use everytime I touch content creation.
1. NWNExplorer
(link)2. GIMP + PLT plugin.
(PLT plugin) (GIMP website)3.
This collection of tutorials.4.
The Custom Content Guide 3.0For blender basics, it really boils down to just using youtube and looking up the specific needs and issues you're running into. But there are tons and tons of great resources for free with a simple search.
Hope some of this helps.