Actipedia is an open-access, user-generated database of creative activism, a joint project of the Yes Men, the Trickster Academy, and the Center for Artistic Activism. It currently contains thousands of activist projects.
You might want to start with the projects that users have said work for change in particular ways (rather than simply being about "raising awareness")—and, for a little more focus, the curated section of particularly effective actions. Just go to Actipedia and click on the "How it works" menu—and judge for yourself whether projects actually do what they're said to!
Soon, projects carried out during Trickster Academy sessions will be featured in a special channel on Actipedia. Stay tuned!