As I mentioned earlier, there are a lot of good books for Power BI developers. It’s hard to select only 5 of them. But if you need a list to start from, then I hope this short list will help you. Just take into account, that it’s rather not a list of books for beginners who require step by step instructions for everything. They are books for you if you want to understand what you’re doing and why. These books are about different topics and not all directly related to Power BI, but each of them is important for Power BI developers. To become an expert in business intelligence you need to understand that there are tool specific methods and tool agnostic fundamental principles.
I tried to select books that will help you to understand the tools (Power BI, Power Query, M, DAX) and to understand what you are really doing using these tools. There will be no ranking from 1 to 5 by book quality or usefulness. All the books are great and equally important. I’ll rather explain when during your work each of the books will be the most useful.
For data preparation in Power BI you need to know Power Query and M language. Read Collect, Combine, and Transform Data Using Power Query in Excel and Power BI by Gil Raviv and you’ll know how you can transform the data.
But you also need to know why you need to transform the data. The main purpose of data transformations in Power Query is to load data from one or multiple sources and to transform the data into a set of tables that can be combined into a good analytical data model (usually start schema). So, the next book is Analyzing Data with Power BI and Power Pivot for Excel by Alberto Ferrari, Marco Russo. It will help you to build the data model.
The next step is to start writing DAX measures for all required calculations. Read Definitive Guide to DAX, The: Business intelligence for Microsoft Power BI, SQL Server Analysis Services, and Excel, 2nd Edition by Alberto Ferrari, Marco Russo.
And then you’ll need to visualize your data. And you’ll need a good introduction into data visualization. Totally tool agnostic introduction. Not a book about “click button #1 and then button #2”. But an explanation why you have to click all those buttons, what chart elements will be useful and what chart elements you can disable in each specific case, what colors you have to chose. A book about fundamental principles that will work well for either a sheet of paper or for Power BI. Read Storytelling with Data: A Data Visualization Guide for Business Professionals by Nussbaumer Knaflic.
On this stage (visualization) you’ll often need to use DAX again to add dynamical titles, captions and other elements to your report. And you’ll probably get first insights from the data that will make you go back to Power Query, data modeling and DAX to bring more data into the report or to reformat the data so you can make your visualization even more insightful.
But there is one more important subject and book. You can know Power Query and M well, you can build good data models, you can know DAX and you can make insightful visualizations. But one data pitfall on any of the stages (staring from data preparation) will make your work useless or misleading. This is why I highly recommend to read Avoiding Data Pitfalls: How to Steer Clear of Common Blunders When Working with Data and Presenting Analysis and Visualizations Ben Jones.
I’ll be writing more book reviews, there are other great books for deeper understanding of data modeling, data visualization, good and misleading charts and so on. I also decided that I want to understand tool agnostic core principles and history of what I do nowadays in Power BI, so I even have Playfair’s Commercial and Political Atlas and Statistical Breviary (published first time in 1786) on my bookshelf. Well, my copy is just a facsimile. And I’m preordering some new books on Amazon. I want to read them all! (I mean just the best of them).