This is, by far, the best step by step for the two primary ways for installing linux on the chromebook. Why would you do that? For reasons that are pretty geeky, but awesome (see below).
How to Install Linux on a Chromebook
Do you need Skype on your Chromebook? Do you miss not having access to games through Steam? Are you pining to use VLC Media Player? Then start using Linux on your Chromebook.