Valve has expanded the Game Hub functionality of Steam by now including a Game Guides tab that is currently in beta. This new feature will allow users to publish their own guides and directly embed YouTube videos or screenshots saved in their Steam cloud.
Taking a quick look, I saw some hastily thrown together "guides," but that's to be expected at this point. With established websites centered around offering this information, it could be a while before we see content on par with what you would find on, say, GameFAQs. For now, though, quick tips, videos, and even some mod advice will do.
More generally speaking, I don't often find myself browsing this area of Steam, but if it's going to be further fleshed out with features like this, that might have to change.