Player-run site for all things North American Scrabble. If you're interested in playing in a tournament, start here. Also, I did a volunteer design project for the site! My designs will be implemented soon!
Internet Scrabble Club (ISC)
Online server for playing Scrabble against people all over the world, as well as AI of varying skill levels. ISC is where I discovered the competitive Scrabble scene.
Mind Sports Academy
Mind Sports International is a games startup hoping to capitalize on large-scale board+card game / eSports events based on their parent company's poker events model. This is their most up-to-date site, currently endorsed by both Hasbro and Mattel.
Hasbro-endorsed organization for North American Scrabble.
Mattel-endorsed organization for international Scrabble.
There are also country-specific associations around the world. Typically a Google search of [country] + Scrabble will return the organization for which you're likely searching!
Fun study tool for learning the dictionary through "word walls" of alphagrams. Includes 2014's "OWL 3" and 2015's "CSW 15".
Breaking The Game / Words of Wisdom
Scrabble's version of Doyle Brunson's Super System. Written by one of my Scrabble mentors and legends of the game, Kenji Matsumoto.
Windows-only (sadly) Scrabble AI that focuses more on inference and defense than Quackle. Has lots of potential but has not been recently updated.
The Scrabble AI that revolutionized the way people learn the game.
Third link down. Only comes with the international lexicon. If you're set on studying the "OWL 3" (American lexicon) and need a copy of the lexicon, feel free to send me an email. Or just use Aerolith.
Social media and Personal sites
Learning Scrabble Words (blog)
Insightful blog by 2006 NSC runner up Geoff Thevenot on learning the words.
Mack Meller (personal site)
Introductory tutorials for new tournament players by Scrabble's most legendary youngster.
Scrabble Snippetz (Facebook group)
The largest worldwide Facebook group for tournament Scrabble.