Hex Strategy Making the Right Connections
Hex Strategy: Making the Right Connections is a book written by Cameron Browne. It was published in 2000. The book is devoted to Hex and covers several aspects of the game: strategy, theory, and computer Hex, among others.
Although the opening chapter is not completely up to date as it deals mainly with non-swap Hex, the rest of the strategy advice is totally relevant. Cameron Browne used Richard Rognlie's server and forum to sum up the advice of dozens of expert players.
Cameron Browne's website