Fellow Germans Fenchel & Janisch have a great tutorial that goes through the basic microphones and how each one effects the noise, ambiance and directionality of voice.
Audio, as many of us know, is 50% of the video experience, and a world on its own, demanding a high level of training and expertise. Starting with what gear to buy – microphones, recorders, cables (yes! more gear! yes!) through what gear to use for each scenario. Sounds familiar?