Annemleone- along with period ephemera as suggested (Ebay!!) you might also look to any old family members or older people in your community. This would be a good excuse to visit nursing homes, as well-you've no idea how thrilled they'd be for visits from interested strangers! Just get them talking and you'll get a ton of interesting fodder. I was luck enough to have a lot of old relatives (my GGM lived to 100, as many of my relatives did) so I got lots of perspectives on the depression, rural southern farm life and life in Chicago during the 20's and 30's. My Dad grew up in Mississippi and Chicago, even remembers his first abrupt introduction to Jim Crow laws while traveling by train to Mississippi as a small boy, and the anger he felt at the inequity is as strong today as it was then. To hear these stories first person is priceless. So, ask an oldie for their stories and use a recorder or take copious notes. Once they're gone, their stories go with them, unless we're diligent!