The Elder Scrolls IV: Oblivion Tips

Daedric Quests (Vaermina)
Ontus Vanin in Talos Plaza can clue you in to the lacation of Vaerminas shrine. you need to offer her a black soul gem. once you complete the quest that she gives you, you recieve the skull of coruption (a staff that makes an evil clone of the target, its quite fun, really)