The community for PowerBI and PowerBI Desktop has been growing. I have compiled some great resources that will help you quickly learn about Power BI Desktop.
Good Books to Read:
My favorite book I have read so far has been Rob Collie’s Power Pivot and Power BI. This book is not only contains super applicable information on DAX but Rob is so Funny. Jokes about Star Trek, power Excel users in the office, whatever the topic he makes it interesting. This is an easy read and he actually had me laughing out loud. Also, I have been able to see Rob one time do a seminar at the Data Insights Summit in Seattle and his comical humor shown through.
The book Learn to Write DAX was extremely helpful to begin working on the basics of DAX. By the end I really started to understand and was able to apply more advanced techniques. Matt Allington has a straight forward approach to helping you learn quickly.
For learning R I read Learning R which is a great resource and provides a good R foundation. There are lots of practical examples that will quickly help your R understanding. Caution, this is not for the faint of heart as this book is TECHNICAL.
To start off understanding Power BI and the concept of the tool and service start by checking out these great YouTube videos from Microsoft:
If you want some formal training you can take this course that is provided by edX.org:
Once you’ve been exploring the Power BI tool you will most likely have additional questions about DAX (Data Analysis Expressions). This wonderful site www.daxpatterns.com will be your Bible for anything related to DAX.