I don't know much about modding Morrowind but these are the relevant links to modding it.
OpenMW - Coming soon™. Morrowind 2.0.
Knots' guide - Supposed best way to overhaul the game. Here's an alternative for a particular
dead link though it seems it's all dead now.
MGSO - Easy way to overhaul the game, not the best but it's acceptable.
Trainwiz's guide - Has some essential mods.
Backed up Morrowind mods
Emma's mods - More mods by a good author.
/v/'s guide - Probably really bad.