Just returning to chess in 2013 after 50 years in the business wilderness!
I have managed to get to a 1,200 rating in live games.
However, I also study tactics in learning format (rating format is too fast and if you make a mistake, you never get feedback on what it was - a Chess.com omission!),
I study Chessmentor lessons with Silman. The latter are truly amazing, especially the annotated games of Tal. If only there was music by Puccini, Tal would make fantastic and romantic opera - Queen sacrifices (Puccini's heroines have a bad habit of dying!), and finally a dramatic climax (in chess, the death of the dreadful enemy King).
Having passed through the 500-1,000 ranks, I have become aware (as a life-long educator) of the need for a basic program to assist novices with the basic principles of opening strategy - some appear to have no idea of what to do when they sit down at the chess board. I have a submission to Chess.com, lest we lose these players from the chess world.
This is not about "teaching kids" as one put-down had it, but of giving back something which I had learned. Teaching principles is better than teaching specific openings or tactics, or (cruelly and fruitlessly?) letting them learn by their own mistakes.