SQL Select Queries with JOINS for dummies

To work with WFA, I often say, you don't have to be a developer, and I stick with that statement.  However, when we want some decent userinput, we will have to write a SQL Query every now and then, and although a simple select query is easy to learn, whenever I start talking about "JOINS", they tend to get lost.  In this tutorial I will try to teach you why we need joins and how they work.