When someone offers you gaming material for free, you say "YES!" Here's a host of free gaming material, perfect for anybody just getting started in the world of Pathfinder!
Player's guides for our adventure paths have been a staple since the very beginning, starting with Rise of the Runelords! Containing tips on which classes fit the campaign the best, along with traits and equipment, the Player's Guides serve as an invaluable aid to players and GMs looking to start a Pathfinder Adventure Path.
The Pathfinder Modules "Dawn of the Scarlet Sun", "Master of the Fallen Fortress", and "Risen from the Sands" were a part of the Free RPG Day promotion, along with the now-infamous "We Be Goblins!" (and "Too!" and "Free!").
And for our last free adventures, get in the wayback machine! "Hollow's Last Hope" was one of the first places that introduced our world of Golarion (yes, even before "Burnt Offerings") via the town of Falcon's Hollow! Another adventure "Revenge of the Kobold King" continues the mini-campaign in Falcon's Hollow, which is set after "Crown of the Kobold King". Since these last adventures were made for 3.5, you may also want to take a look at the Pathfinder Roleplaying Game Conversion Guide. If you're just getting started in Pathfinder and have a copy of the Beginner Box, check out the first and second demos (not to mention the GM Kit, Player Pack, Pathfinder Society Character Creation, and Transitions PDFs).
Both the Adventure Card Guild Guide and the Roleplaying Guild Guide contain all the details that you need to get started in our two Organized Play programs, but that's just the beginning! The GM 101 , GM 201, and Kid's Track PDFs for the Roleplaying Guild give you additional resources and advice on how to run events and games for your local group. The Faction Journal Cards and The Story So Far PDFs give players a better overview of what's going on, while the GM Star Reward Chronicle Sheets gives GMs access to special rewards for running Pathfinder Society games. And speaking of Pathfinder Society games, "Ambush in Absalom", "Fane of Fangs", "In Service to Lore", "Phantom Phenomena", and "The Silverhex Chronicles" are great introductions to the Roleplaying Guild arm of Pathfinder Society, while "On the Horizon" and "Demonic Politics" introduce organized play seasons for the Adventure Card Guild!
Recently updated with the errata for the Advanced Class Guide, the Pathfinder Reference Document contains almost all of the mechanical references from our Pathfinder Roleplaying Game hardcover line of books. We're always looking to improve the PRD to make it more useful for GMs, so please don't hesitate to give us your feedback!
Since the very beginning of Pathfinder, Paizo has allowed for fans to create and share their own material using our campaign setting of Golarion. The Community Use Project allows for amazing resources like PathfinderWiki.com, the Archives of Nethys, and the innumerable flyers and handouts made by our hard-working volunteer Venture Officers of the Pathfinder Society! I would be remiss if I did not mention the Wayfinder fanzine and Pathfinder Chronicler anthologies, one of the first Community Use Projects—and still going strong with the 14th issue in the works! If you're looking for character sheets, holy symbols, regional flags, they are available (along with a host of other things) in our Community Use Packages, and if you want to make your desktop, phone, or tablet look a bit shinier, we have many, many wallpapers for you as well!
Hopefully this post has illuminated you to the amazing array of resources available to you—without ever having to open your wallet!
May your next dice rolls be successful ones,