Serpent's Skull Player's Guide
The Serpent's Skull Player's Guide, a free PDF supplement written by Mark Moreland, James Jacobs, and F. Wesley Schneider, accompanied the release of Souls for Smuggler's Shiv in late July 2010.
“This guide seeks to aid players preparing to take part in the Serpents Skull Adventure Path, to arm them with spoiler-free details and rules elements useful in the forthcoming challenges, and to help create backgrounds that easily mesh with the campaign.
Along with advice for players of every race and character class in the Pathfinder Roleplaying Game—including those in the newly released Advanced Player's Guide—details on Sargava, the country in closest proximity to the campaign's events, and of the Jenivere, the ship conveying the PCs to adventure, should help ground players in the circumstances and events of this new Adventure Path.
Those looking for even more details and options for exotic adventures should take a look at Sargava, The Lost Colony.
”