Search for any game on the internet and you'll soon find yourself unable to move for forums packed with hints, puzzles solutions, build queues, and all sorts of handy info. It's a little disparate though and rarely rated or vetted. Valve are trying to refine the system with a new guides feature for Steam.
More on how it works below.
Anyone can now write a guide, or a tip, or a handy helper within Steam and then attach it to a game's community hub. They're easy to access within a game too because you just need to press Shift + Tab to bring up the Steam overlay and there's a button there to load relevant guides for your perusal.
The guides support images and video embedding so they're a lot nice looking than the game guides of old.
Now, I did say that the guides were rated and vetted, this isn't by Valve though. As it is part of the Community Hub, each guide can be rated and commented on by other Steam users. So if a guide is good it will rise to prominence among the other content on the hub, if it's got factual errors it will likely be down-voted into oblivion or the author can go back and edit it to perfection based on the comments.
A neat little system.