The Mist User Guide describes all aspects of the Mist user interface.
The Mist User Guide is broken up into three parts. The first part provides a step by step walkthrough for building assets for use in a sample cube, leveraging the AdventureWorksLT database. The second part describes each Mist editor, tool window, and ribbon button. The third part includes miscellaneous topics that don't fit into the first two groups.
If you have questions that aren't addressed in this guide, you can search and post in the Mist forum for help.
While the forums are the best way to get answers, if your question contains proprietarty, or other, information that you would prefer not to post publicly, private email support is available at firstname.lastname@example.org