There are guides to many of the classes in Pathfinder, but the Guide to the Guides is conspicuously missing a guide to all of the myriad races of the game.
Here’s a link to the discussion of this guide on Paizo.com: http://paizo.com/threads/rzs2p7m6?Cartmanbecks-Guide-to-Pathfinder-Races
Now, I want to preface this guide by pointing out that my ratings are going to be ALMOST completely based on optimization ability (though once in a while I will rate something a bit higher if it’s super thematic and fun). Any race can be made into a decent character of any class if you make the right choices, but some races just work better and are more optimized for some classes.
The structure of the writeup for each race will be as follows:
Race name - Classes that work well and their color ranking
Quick description of the race
Racial Traits - These are the racial abilities that the race normally gets, and how useful they are.
Alternate Racial Traits - These are the racial abilities that you can replace normal racial traits with, which can sometimes be way better or way worse than the original trait. The trait that is being replaced is shown in [brackets] right next to the name of the new trait.
Classes - Here I’ll list each of the standard base classes, mentioning any archetypes that work well for the given race.
Racial Favored Class Bonuses - Here I’ll list all of the favored class bonuses that are specific to the given race with their rating.
Racial Archetypes - Here I’ll give a quick description of the archetypes that are specifically available to the given race, most of which come from the Advanced Race Guide.
Prestige classes - Here I’ll give a short list of prestige classes that work very well for the given race, including what base class/classes you’ll want to use to fulfill prerequisistes
Racial Feats - I’ll give a quick description of what each race-specific feat does and its rating.
Red = This is a really bad choice. Avoid it.
Orange = This isn’t a very good choice, but you could do worse.
Green = This is a good, solid choice, though there might be slightly better ones out there.
Blue = This is a great choice, I love it.
Sky Blue = You really should use this. It’s the best option out there.