For player characters, the choices for races and classes can be freely chosen from The
Pathfinder Core Rulebook, the Pathfinder Advanced Players Guide, (with the exception of Hero Points), the Kingmaker Players Guide free pdf, and Barbarian Traits pdf
Clerics may choose to have Exalted Domains. See The Genius Guide to Exalted Domains of War & Ruin, The Genius Guide to Exalted Domains of Light & Lore and The Genius Guide to Exalted Domains of Storms and Savagery pdfs.
All spellcasters do not choose metamagic feats. Instead the alternative system from Ars Metamagica pdf will be used. Note that Metamagic rods are not allowed.
A few house rules, borrowed from previous sources that I quite like. Firstly feats:
Poison Use The character no longer posions himself on a roll of ‘1’.
Weapon Panache When using a light weapon this character may use their Charisma modifier as a bonus to hit instead of strength.
Secondly, racial weapons. If a character of a certain race can use martial weapons then race specific exotic weapons are martial for that character.
For an online resource, make sure you go to the Paizo Pathfinder RPG Referance Document and not the D20 PFSRD (link intentionally not given) as this has a lot of additional content that may not be included in this campaign.
During the Game
In game the following additonal rules are incorporated.
Hot Pursuit the chase rules from Tome of Secrets This incorporate a method that gets away from comparing Move rates.
Making Craft Work A different method for computing Craft Difficulties and times.
Critical Hits Deck – reduce the damage multiplier by one and draw a card.
Critical Fumbles Deck
Plot Twist Cards – one per player, replaced when spent.
Varient Drinking/alcohol rules from an ENWorld article.