The five novels that make up the Song of Ice and Fire series are not the only official works related to the series that have appeared. There have been several spin-off products and companion guides complete with their own maps and illustrations, to say nothing of the materials produced by HBO to promote the Game of Thrones TV series.
First up was Dragon Magazine, the official magazine for the Dungeons and Dragons roleplaying game. In March 2003, in issue #305, Dragon published Arms of the Kraken, a novella made up of the ironborn chapters from A Feast for Crows (apart from the final Victarion chapter). Two issues later, in #307, Dragon published a Song of Ice and Fire-focused issue featuring an interview with George R.R. Martin and ideas on how to run a D&D campaign set in Westeros using the 3rd Edition game rules. Of particular interest was a map. To my knowledge, this is the first official map of Westeros to have been published outside the novels themselves. The map was drawn by Mike Mayart. Remarkably, this was the first official map to combine the North and South into one map; the only previous ones to do this were due to fans amalgamating the existing maps manually.
Two years later Guardians of Order published the first official ASoIaF roleplaying game. A Game of Thrones Roleplaying, using an adjusted version of the d20 rules used for D&D, was published in late 2005 and featured an entirely new (and rather swanky) map of Westeros created by Keith Curtis. Sadly, Guardians of Order went bust shortly after this product shipped. In 2009 Green Ronin Publishing released a new version of the roleplaying game using their own rule system, but retained Curtis’s map. A new edition was released in 2012.
Green Ronin went on to release a series of expansions and adventures for the roleplaying game, the first of which was Peril at King’s Landing. This adventure features a new map of King’s Landing drawn by Andy Law. The 2012 edition of the RPG comes with the adventure and map included
With the launch of Game of Thrones in 2011 and the resulting boom in sales, the publishers started assembling new boxed sets of all five books. HarperCollins Voyager released a boxed set with all seven volumes (counting the two-volume editions of the third and fifth novels) along with a nice map of Westeros and the Free Cities. Limited editions of this box set also included similar maps of the Wall and King’s Landing.
More substantial and interesting new maps appeared in two further companion products, which are notable enough to get their own separate entry: The Lands of Ice and Fire (2012) and The World of Ice and Fire (2014).