This review by Matthew Pook is worth considering if only for the terrible pun of the title, Tome Team.
Given the lack of a sourcebook detailing London within the genre of Lovecraftian investigative horror, Bookhounds of London is a much, much needed resource. Although its focus is primarily the book and the booktrade, the information on outré tomes is equally as relevant to Call of-, Realms of-, and Shadows of Cthulhu as they are Trail of Cthulhu. The background to London is equally as relevant and useful to all of these games.