There are many free resources on the web, but not all are created equal. The Leader to Leader Institute, which was founded as Peter F. Drucker Foundation for Nonprofit Management, is one that contributes a variety of useful and inspiring resources. I’ll point to a few:
Their on-line journal has many free articles: Leader to Leader Journal.
Another useful resource is the Thought Leader Gateway, which includes an ability to search for articles, interviews, and videos by author. For example, this link will send you to a short biography of Peter Drucker and list Drucker resources available from the Institute.
Finally, they are challenging organizations to ask and answer five essential questions: What is our mission? Who is our customer? What do the customers value? What are our results? and What is our plan? Can you answer those questions for your organization? Could you tell me the answer in 3 minutes or less?