A well-composed party is crucial to success and survival. Understanding the challenges which your party will face and the skill sets required will help you and your party to select classes which can make up a well-rounded party.
Pathfinder - Player Resources
These resources are intended to help you be a better player. While my character optimization articles focus on making more effective characters, these articles focus on things that are often less mechanical, but are no less practical or useful.
Sometimes it can be fun to build a party with a cohesive theme. This article provides several example themes, and suggestions for building functional parties around those themes.
A conceptual guide to dungeon survival in Pathfinder.
Sometimes you don't know what to play, or sometimes you just need a random NPC. This article provides tables to build out the basics of an interesting and functional character.