List of Spell NPCs

You can buy spells from the vocation guild leaders and spell instructors in each city. There are some exceptions because reasons(probably because they do quests or are important vendors). These spell NPCs can sell spells to all vocations. If you ask me why a knight spell instructor should be able to sell spells to a sorcerer I will tell you to shut your stupid fucking face. I may change it later so these NPCs sell to specific vocations. 

All sorcerer guild leader: except for: Eremo, Malunga, Myra, Tothdral, Zoltan
All druid guild leaders except for: Charlotta, Elathrial, Maealil, Padreia, Rahkem, Ustan, Hjaern
All paladin guild leaders except for: Elane, Legola, Razan
All knight guild leaders except for: Gregor, Trisha