Over a two-year period, 3nigmat1c put together an amazing compendium of match-practical knowledge on the SF4 series. His articles cover a wide range of critical skills such as frame traps, option selects, meaties, safe jumps, and much more. Each article is accompanied by several video examples, showing every concept in action.
This is an incredible resource for anyone who wants to learn the technical side of competitive Street Fighter 4, and all of it still applies to SSF4AE2012. In addition to his SF4 Game Mechanics series, 3nigmat1c wrote two extra articles on avoiding projectiles and punishing mistakes.
Most of his examples revolve around Balrog, but the underlying concepts can be applied to just about about any character in Super Street Fighter 4 Arcade Edition 2012.