Things You'll Need
Instructions
Setup any visual aids that you intend to use as props before the game begins. The players may need maps of the city they are residing in, pictures of the nobles they are dealing with, or maybe even print outs of the royal decree from the king that was just delivered to them by a messenger.
Create non-player characters who seem like enemies but are actually potential allies, and characters who appear to be staunch allies but are actually enemies in disguise. In a campaign heavy on political intrigue the real bad guys aren't the vicious monsters in the dark dungeon, but rather ambitious individuals who will not be openly displaying their evil plots.
Spend a good deal of time fleshing out all of the major non-player characters so that their words and actions are believable. Role-playing is at the forefront of any political intrigue based session, so your representation of the various people that the players will meet can make or break the entire game.
Set a focus on non-combat related skills and feats, and make sure that your players are made aware of it before rolling up their new characters. However not all of the characters need to be fast talking social masters with a dozen ranks in the bluff skill. The game can actually be made more fun if one or two of the characters play dumb half-orc fighters with no social graces whatsoever, to frequently get the other characters in embarrassing situations that are hard to get out of.
Remember that in a political oriented game where combat is an afterthought that veiled threats and easy promises that won't be kept can be much more deadly or effective in overcoming obstacles than swords or spells.
Consider making the stakes of the game more personal for the players by allowing them to earn their own strongholds or gain stewardship over an entire town. They will be much more inclined to work harder at playing the political game if they think losing might result in their peasants being killed during an invasion or that they could potentially lose ownership of their keep to a rival.