The SQLBI youtube channel is a great place to learn about all sorts of DAX and Tabular engine topics. They also have a playlist of short videos dedicated to DAX Studio as part of their DAX Tools courses.
An introduction to DAX Studio, from downloading and installing to running basic queries
An overview of using DAX Studio to optimize your tabular models.
A full feature review of all the important features in DAX Studio (as of the 2.10.2 release)
A tutorial on how to tune your DAX queries and measures using DAX Studio
This video introduces new features that improves the debug experience in DAX Studio: tooltips for columns statistics, capture trace of all queries, and definition of dependent measures.
DAX Studio introduced important features to analyze the query plan and find bottlenecks in your DAX code