Oregon has excellent resources for non-profits and volunteers, whether you run one, serve on a board, want to work at one, or want to start one:
1) Connectipedia (see 6/17/08 Oregonian article, by Steve Woodward: Nonprofits share the knowledge)
2) TACS: they write the Oregon non-profit source book, without which we would all flail about helplessly, with or without profit.
3) Nonprofit Association of Oregon
4) Volunteer opportunities: the most excellent Hands On Greater Portland
5) Don’t forget checking with your local public library, where you can find the Encyclopedia of Associations (and its online counterpart, Associations Unlimited).