All that you really need to know about Scrabble in the UK is that the book used for all tournament play is Collins Tournament and Club Word List, the first book listed below. If you don't have one of these then it is a vital purchase! See Tilefish for details on how to purchase both books shown below.
Collins Tournament and Club Word List
This is the authority for all tournament and club play. All tournaments which are either run and/or rated by the ABSP use this reference work as the arbiter for determining the validity of every word played.
Contains a strict alphabetical list of all valid words of length 2-9 letters. A separate section at the back then lists all valid 10-15 letter words, avoiding the need for any extra dictionary for adjudicating those rare long plays.
Collins English Dictionary (2007 edition)
This mammoth book is the source of all the new words found in Collins Scrabble Words and provides an excellent backup for club and tournament organisers, as well as being a treasure trove of exciting new entries for word lovers everywhere.
Including a much wider range of words than ever before, the extensive coverage of geographical, scientific, and technical entries has been updated by our team of leading academic experts. Language notes give advice on using the right word in the right place, and thousands of word histories trace the roots of modern English. All this has been complemented with a refreshingly clutter-free design, which is easy to use and easy on the eye, taking you straight to the information you need with the minimum of fuss.
Discover all the latest words as they appear in the language. You can rely on Collins: all our definitions, examples, idioms and usage notes are based on the Collins Word Web - our unrivalled and constantly updated 2.5 billion-word database of today's English. Accessible layout that's easy on the eye, guiding you quickly to what you want. Words are tools for life... and a Collins Dictionary makes them work for you.
The Scrabble Player's Handbook
This is a definitive and free ebook on how to play Scrabble, written by a dozen of the best tournament players in the world. All twelve authors have competed in past World Scrabble Championships and have spent over a year combining their knowledge into this one free Scrabble resource.