I strongly recommend to download and read in detail the “2015 Annual State of DevOps” published by Gleanster and Delphix. It’s free and very informative!
If you don’t want to leave your contact information and appears in their marketing list, you can found the key infographic in this article (text in French).
By the way, if you’re in the IT business or if you have some concerns about the IT department in your company, you must read this book: “The Phoenix Project”. It’s a tale about DevOps. It’s really funny, it’s eye-opening, it’s inspiring, and you can’t read it without thinking “I know so well that feeling, we’ve experienced it during that hard project … years ago“.