Right good place to look for mods is
http://www.mwmythicmods.com/telesphoros.htm some links may be out of date but just google and usually you can find them. Personally im using...
(EDIT: these tops mods dont really change the game just make it look prettier and add atmosphere, just paste em or Crt-F them into google/telesphoros page for DL links)
Morrowind Graphics Extender & FPS optimser (not working on the steam version but add a lot of nice effects distant land AA, AF etc)
Darker Morrowind (good texture overhaul, that mostly keeps with the original style, though check comparisons
here )
Better Bodies (+ clothiers of Vvardenfell) (better bodies models and clothes)
Better Heads (maybe cant remember if I use it, may conflict with the Facepack)
Facepack compilation (better faces though there quite a number of packs)
DarkNuts textures (bunch of weapon, armor creature texture improvments)
Graphic Herbalism (picking herbs like Oblivion plus it removes the part of the plant you harvest)
Real Signposts (speaks for itself)
Better Books (better book textures)
Morrowind Comes Alive (adds random NPC and travellers to towns)
Atmospheric Sound Effects (again speaks for itself)
Children of Morrowind (adds little people to the game)
Lights 300 (nicer lighting)
Seasons (adds seasons for trees etc)
And finally the official (not great) mods off the bethesda website.
Also quite good are Vailitys Mods (add grass and better trees etc) but I find them abit to strong and change the look a lot and can be quite slow on older systems especially if youre usuing MGE.
Other good ones though not for your first play through are some of the expanded/extended city mods, either Morrowind Advanced or Creatures X with where are all the birds? mod and water life (adds more NPC and creatures in the wild etc) and Nessecities of Morrowind (adds need for food drink sleep etc).
Oh and be sure to get the unofficial morrowind patch and morrowind code patch if you want, I dont but they fix a lot of minor things that you probably dont notice.
Phew long post....