Photography Cheat Sheet: what your camera captures at every lens' focal length - wide angle to telephoto
How to use a wide angle lens - using the exaggeration in distance between near and far and the wide field of view to create great photos.
Rokinon 12mm wide angle lens
How different types of lenses 'see' the world: free photography cheat sheet
Wide-angle Lenses and the Landscape . andrew gibson via digital-photography-school