Use Wikipedia and subject specific encyclopedias to identify tales and tale types. These sources can help you understand context, key concepts, and identify readings that can help you to start to dig into your topic. Generally these sources are not things that you would site in your paper; they're intended as starting points.
The print resources here may make it easier for you to discover topics that had not already occurred to you as they present essays on a wide range of issues related to fairy tales in Europe (and elsehwere).