In the thieves guild quest where the mages leave their guild in Ald'Ruhn I cleaned the place empty. Later I felt badly so I donated a large stash of rare items and turned the guild into Ald'Ruhn Rarities Museum.
I had formerly kept most my stuff in the crate out front of Vori's house in Balmora (since she seems to be in Sadrith Mora for some reason I don't think she minds) where I "lived" for a while. Space got a bit too crammped and I moved into Rethan manor when I got it. But I felt wierd having my books and items of illicite (stuff like the Pelgiad Prisoner Log and Odral Helvi's books about his mis-spending)gain on display in a public non-locked place where it could be linked to me. So I moved my rarities into the Ald'Ruhn mage's guild and my illegal items into a locked chest underneath someone's house in (I think) Hla Oad(?)