"Open Advice" is a new book consisting of essays from some 42 community authors; it is available in print form or downloadable under the CC-BY-SA license. "This book is the answer to 'What would you have liked to know when you started contributing?'. The authors give insights into the many different talents it takes to make a successful software project, coding of course but also design, translation, marketing and other skills. We are here to give you a head start if you are new. And if you have been contributing for a while already, we are here to give you some insight into other areas and projects."