Ever since I read his book on "Influence" while getting my Masters degree in Influence Management, I've recommended Robert Cialdini as part of a basic curriculum for anyone wanting to understand how persuasion works. I just stumbled upon a YouTube video where Robert Cialdini explains seven of his most famous principles of persuasion. Even though it's in no way the ultimate resource, I find most people benefit greatly from picking up the "Cialdini basics". As he again points out while promoting "The YES Project", making small significant changes will often result in very big differences while maintaining your integrity.
Better invest a minute or two by looking into this, regardless of what your role is!