Voting is just a small part of political empowerment, knowledge of all of the common forms of political action besides voting. This is usually called “advocacy” and here are links and tips about each form of advocacy. [Note that citing a certain organization’s advocacy information does not imply that we endorse their issues or viewpoints. Cited materials are almost completely generic.]
Some Advanced Knowledge Resources (for highly motivated people and organizations):
StudentPIRGs has a good all-around resource. (“PIRG” means “public interest research group”) http://studentpirgs.org/
From epolitics.com you can download a 44-page guide to doing online advocacy. http://www.epolitics.com/2006/09/26/download-online-politics-101/
Whistleblowing on unfair, unethical or unsafe practices www.whistleblower.org (Called the Government Accountability Project)
Building coalitions (with culturally diverse populations) A 16-part series from the University of Florida: http://edis.ifas.ufl.edu/FY508 The PDF link is at the top of that webpage.
NetAction has an excellent 26-page document on using the Internet for outreach and organizing. http://www.netaction.org/training/index.html
Managing the Media, A Guide for Activists http://tenant.net/Organize/media.html
NetAction Notes 20 on Media Activists http://www.netaction.org/notes/notes20.html
NetAction Notes 47 on Media Activism http://www.netaction.org/notes/notes47.html
The Center for Lobbying in the Public Interest has many resources:
Lobbying tactics http://www.clpi.org/nuts-a-bolts/lobbying-tactics
Advocacy tactics http://www.clpi.org/nuts-a-bolts/advocacy-tactics
More info, especially for nonprofits http://www.clpi.org/