Exploring Electronic Dance Music - EDM Guide
Ishkur's Guide to Electronic Music is worth a visit. This nifty website lets you explore and listen to the nearly 200 different genres of electronic dance music. Each top level genre (house, trance, techno, etc) is broken down into a network of subgenera, with clusters, dependencies and hierarchies represented. There's lots of info presented in a visually engaging way, but the best part of the site is being able to listen to examples of all of the various genres. If you don't know the difference between JPop and Eurodance, this is the place to go.