The Slow Leadership blog has discussion on current leadership and itemises the 8 Principles of Slow Leadership.
The Enneagram Insitute has free resources and a run down of the nine character types and how to understand them.
Mind Tools is a fantastic site with a lot of information on leadership styles and work place management resources. Very helful and information rich.
12 Manage has the Goleman Leadership styles. It also deals with emotional intelligence . A site with plenty of statisitics, information and guidelines for those who would lead.
Changing Minds is David Strakers site on leadership and has a wealth of information and looks at 7 leadership styles. It looks at persuasion principals too. It is a site about changing minds!
Evidence Based Management is coming into vogue so here is a site to keep you up with the pack.