In the monster write-ups there isn't a lot of direction given to how to play goblins. This is the take I've come up with for the games I run. Use it if you like it. Enjoy.
Goblins start out tiny, and nearly all teeth. The more they eat, the more they grow. Not many live long enough or eat well enough to reach the size of a human and it's only the prodigious few grow to a massive ogrelike bulk. Goblins don't distinguish between their different varieties--they're all just goblins. Other races have come up with fanciful names for the bigger ones: "hobgoblins", "bugbears", and other invented subspecie--but much of that is just invention, projecting the habits of a few individuals on a whole race.
In general the biggest goblins rule over the rest who treat them with awe and slavish devotion. That said their teeming underlings, despite their fauning, are ready turn on their leaders and eat them as soon as the group's fortunes turn. Goblin metabolisms are slaves to constant eating, death by starvation is quick and ugly, it doesn't take many failures before a boss discovers another way to appease his hungry lessers.
Because they value food so greatly, they make a great workforce, gladly toiling away for the promise of a meal. Of course, failure to pay often makes an employer into dinner.