first click on the "enchanting" tab... its in the object window.... theres a big list of all the games enchantments that were put on weapons, armor, clothing...
-Right click somewhere on the list and click on new
-In the ID area, give it a unique name for the game to find... Good mod makers use initials or something in front of all the things they add(like I would use kil_enchantment01, kil_weapon01, kil_spell01...)
-In cast type, choose whether its cast on strike(for weapons), cast once(scrolls), cast when used(it shows up in the spell list), or constant effect(the effect is on the player when its equiped).
-Choose what effects you want(up to 8), and choose how much charge it has and how much each cast uses(for strike and use). Then save.
-If your making a weapon, go into the weapon tab and make your weapon, and in the enchantment field, scroll down the list and find the enchantment you made... clothing is in the clothing tab, armor is in the armor tab, scrolls are in the books tab...



-Create a new folder somewhere...
-inside the folder, make a meshes folder, icons folder, textures folder, whatever else your adding, make sure all the folders are the same as in the data files(like some meshes are in meshes\b)
-Then copy all the meshes your mod uses and put them in the right folder, and same with all the other files you need.
-Copy the esp in the new folder too, and put in a readme.
-Select all the stuff in the folder, right click, and there should be an "add to zip" thing on the menu.



Meshes are the files on the computer... to make new ones, you need 3ds Max... a really expensive 3d modeling program. Meshes are all the .nif files. The editor doesn't edit meshes, you can make new objects like weapons and stuff, but you have to use whatever meshes are in the morrowind folders.

Not sure what you mean by ai's... if you mean make new npc's, then the editor can do that... if you mean, change how the npc's walk around, react... you need to use scripts.