As others that I have seen here, I will put in my PC my GOTY copy of Morrowind, of course with Tribunal and Bloodmoon.

Of course I ask for help about good utilities to place before start to put mods.

Any advice is very welcome.

Having re-installed MW recently, I remember the process well enough

Must have patches

http://www.nexusmods.com/morrowind/mods/19510/?

http://timeslip.users.sourceforge.net/exeopt.html

http://www.ntcore.com/4gb_patch.php

http://www.theassimilationlab.com/forums/files/file/1060-previous-patches-unofficial-morrowind-patch/

... in that order.

Tools to manage mods:

https://sourceforge.net/projects/mlox/(mod order)

https://code.google.com/archive/p/mlox/downloads (clean and merge leveled lists)

http://www.nexusmods.com/morrowind/mods/27588/? (incompatibilities, installer, saved game cleaner...)

also http://mw.modhistory.com/download-95-15255

Danae already posted very good list, so I will just add a few more I frequently use:

Enchated Editor - the most low level editing you can get. Extremely handy, plus there is no alternate program that would be capable of doing same stuff.

BSA Unpacker - allows you to unpack bsa files if you need vanilla meshes/textures for editing and stuff

Optimizer Texures 0.83 + abot's settings - authomatically converts all given textures to best fitting format for morrowind, creates missing mipmaps etc. A lot of mods have unoptimised textures, this tool can easily reduce 200mb mod to 40mb while preserving the almost the same level of quality (the sizes are just example and depend on the actual textures in the mod)

Other tools that might be handy:

AnimKit - if you want to mess around with animations

Blender 2.49b + NifScripts - if you want to do some modelling

BSA Browser - also allows creating your own bsa files. For unpacking I prefer BSA Unpacker since it seems faster

Mod TEST chargen v2.5 - mod that skips character cration and puts you immediatelly to seyda neen with maxed stats and "Qube of giving" that is capable of spawning armor/weapons/tools etc. Handy for quick testing

MWEdit - has better error checking when writing scripts and is also capable of compiling MWSE scripts as far as I know

TESFaith - should you need to completely move some landmass mod to new position because of conflicts

TESFiles - very handy tool. You just select esp and it will export all referenced icons, sounds, meshes and textures to selected folder and reports missing ones. Good when you are about to release a mod and need to check if you have all files you want.

TESPCD - good for detecting mod conflicts

Sorry, too tired to hunt for the links.

http://download.fliggerty.com/download--931 is another must have IMO.
Put in it Meshes folder, run something like this:

nif_tx_strip.exe --local --back_slash --no_texture_path > out.txt

faster than Chiktika Fastpaws
, look for -> inside the out.txt log file, enjoy

Overunity is another a-must-have tool at least for modders.

http://www.gamesas.com/topic/1505187-need-help-packaging-mods/

Wait. Is the OP wanting to create mods, or just add some to his game?

If the latter, I would suggest perusing a couple of the pinned threads at the top of the forum. Much of the information is a little old, but most of it is still valid.

To add mods for the first time, you will need a mod organizer (one of the most overall useful - Wrye Mash) and a load organizer helper such as mlox. After those two, you might need a good mod cleaner such as tes3cmd (read the instructions carefully before you use it). The rest of the tools listed here are a bit more advanced and specific to certain problems that may, or may not, arise. All of these have links above in other posts.

Once you have these, it's a good time to just consider what you want in your game and how you want to change it. The pinned threads will be very helpful here as there are too many mods out there to list and describe them all. Look at categories on GHF, MMH, and Nexus for the areas you are interested in. Mods available for download at these sites will have at least basic descriptions and some of them (particularly Nexus) will usually have images to view and posts from other users.

Also, run through some of the videos from DarkElfGuy's Showcase thread. He does a marvelous job of showing and walking through part of a lot of good ones. (Leaving out spoilers.)