These are a few links that I’ve found useful in my work.

Consensus Basics

This is a fairly quick, very clear explanation of what consensus is and how to use it.

The Future Search Network

A voluntary worldwide network of individuals committed to participative whole-system planning.

Free Management Library

An outstanding resource for the very basics in non-profit (and for-profit) management.

National Coalition for Dialogue and Deliberation

This is an excellent starting place for how to have hard conversations.  See also The Public Conversations Project.

Mediation Training Institute

All mediation, all the time.  I can heartily recommend their monthly newsletter - very informative, yet not too frequent.