The Strategic Planning process
Information about Nonprofit Strategic Planning covers every aspect of strategic planning. It is adapted from the guidebook, Field Guide to Nonprofit Strategic Planning and Facilitation. A half page overview is followed by information about key terms, different planning models, etc.
Crafting Effective Mission and Vision Statements is a book offered at Idealist.org, which allows helps recruit volunteers and staff for nonprofits. The Nonprofit FAQat Idealist answer many questions about nonprofit organizations.
The Alliance for Nonprofit Management offers an article entitled, What's in a mission statement?, as well as other resources.
Tony Pederis'Fundraising Forum has a guide, Don't Make Your Organizations Statement of Purpose a Mission Impossible
The Foundation Centerhas a detailed bibliography of resources on mission statements.