Perhaps the most pertinent and frequent question I'm asked when teaching Tableau is, How do I get my data ready for Tableau? I find this difficult to answer for two reasons. Firstly, it's hard to know exactly what the student means by the question, and secondly, it's outside the scope of the class. Let's consider both these reasons.
There is a range of possible meanings for How do I get my data ready for Tableau? At the simplest end of the spectrum, some who ask this question just want to know what an Excel spreadsheet prepared for use with Tableau should look like. It suffices to show such students the Sample Superstore dataset that installs with Tableau and explain that the addition of human-readable content, such as comments and text boxes, may make the file difficult or impossible to connect to and that the inclusion of totals in the body of the spreadsheet would skew results. Other students wish to understand the basic data structure...