Project Management is the application of knowledge, skills, tools and techniques to project activities in order to meet project requirements and objectives.
The PMI Methodology proposes a framework that distributes project management activities into discrete elements : the Processes. These processes are gathered in 5 Process Groups and relates to 10 Knowledge Areas.
Below some useful papers about techniques and methodology to help the PM in his duty.
Scope Management
Setting up the Work Breakdown structure : Applying the Work Breakdown Structure to the Project Management Lifecycle
Stakeholder Managament
Stakeholders identification and analysis techniques : What to do when Stakeholders Matter