Here are a few LocalWiki informational materials for you to use:
LocalWiki one-pager: flyer_overview.pdf (made for the 2014 Code for America Summit)
....
Older (possibly out of date) materials
Early 2014'ish LocalWiki basic info powerpoint: LocalWikiInfoDeck.pdf (2.3MB)
2013'ish one-pager: LocalWikiBasicInfo.pdf (1.2MB) -- From 2013 Knight Foundation Media Learning Seminar in Miami.