BoardSource (formerly the National Center for Nonprofit Boards) provides answers to a range of common questions about nonprofit boards.  Areas covered include: Board Composition and Structure, Board Development, Board Member Responsibilities, Board Meetings, Financial Issues, Fund-raising, and Legal Liability Issues.

Short articles on effective governance from The Alliance for Nonprofit Governance.

Information about the roles of boards in the governance of nonprofit organizations, part one of a two part series which can be found from the link aswell.

This Nonprofit Quarterly Article by Daniel Yankelovich describes the core elements of a "Dialogue" and the role of this in building strategic relationships.  Effective nonprofit boards often feature a healthy dose of dialogue in their meetings and interactions.