A SWOT analysis is an exercise which can help identify strategies for your campaign.
It looks at your organisation's or community's internal Strengths and Weaknesses, external Opportunities and Threats. This helps you to see what positive aspects you can build on and potential problems you need to deal with.
Community Tool Box, a website from the United States, has an easy to follow description of how to do a SWOT analysis: http://ctb.ku.edu/en/tablecontents/sub_section_main_1049.htm .
Also, look at non-profit marketing professional Chas Grundy's Strategic Planning Blog. His SWOT Analysis Toolkit could be useful: http://nonprofitchas.com/2008/12/21/strategic-planning-swot-analysis-toolkit/