you should check out Teleshphoros' List O' Mods
. it is by far the best list of Morrowind mods i've ever found, complete with descriptions and download links.
you might also want to have a look at this thread
over at OctopusOverlords about the Morrowind Plug-In DVD put together by Blackhawk (an idea started at GG). the official distribution effort is over, but it's a great disc if you can get someone over there to send you a copy