heres how to put modes on Oblivion:
step 1: go to MyComputer
step 2: than to LocalDisk C:
step 3: than to Program Files
step 4: find Bethesda Softworks {folder} in side that folder you will see another folder named Oblivion in that folder you should see the Data folder go in it as well
step 5: now with in that folder if this is your first mod tobe placed in your game you will not see thies folders
Folders: Textures Meshes etc you will have to make thies folders as like what you did in morrowind.