Valve has launched a new feature on Steam called Steam Guides. It's a community driven database of hints and tips for games that are available on Steam, and there's already over 2,000 guides available.
Valve's website explains: "Steam Guides are player-created references for games and software, created by fellow members of the Steam Community... You can find guides in the Steam Overlay or from any Community Hub. You can easily find guides from whatever game you are playing."