One of the issues is that NWN 'emitters' are NOT the same, exactly, as 3dsmax/gmax emitters. By that, I mean that NWN engine completely ignores a huge amount of the possible settings that are available for emitters.
Your best bet though, on learning emitters that is, is to go
3dsmax Emitter Search on Google and start picking through the list. You COULD try to search on Gmax, but the search results I found for gmax are really really dated since Autodesk completely stopped advertising and all support for Gmax around 2002 or so...
Regardless particle emitters can be used for light effects, smoke effects, flying rocks and likely thousands of other things. The settings are the same in 3dsmax and Gmax, although there may be a few extras that are added by using 3dsmax instead of Gmax.
Learn the basics first, then proceed into the mathematics OR more detailed options as you gain experience!
Have fun, and it can be fun, it can also be a huge heart/headache as well!
