Archivists Rick and Megan Prelinger will be the guest speakers at tonight's August meeting of the San Francisco History Association at St. Philip's Church in Noe Valley. The pair will present an overview of the sociohistorical resources available in their collection at the Prelinger Library in SOMA, which brings together a range of items including ephemera, periodicals, maps, and books dating back to 1888. The talk will provide those new to the library an introduction to what lies in its stacks, to the films available in the Prelinger Archive, and to the library's value as a unique research institution in San Francisco. Doors open at 7, talk begins at 7:45. Admission is $5 for non-SFHA members, free for members.