This is for people who are new to unix, especially people who are new to unix & new to Super Dimension Fortress (SDF), a public access unix system.
I sometimes hang out in the chat rooms on SDF, & almost every day someone enters who has recently created an account & asks how to get started using unix & the features of SDF. It's an awkward situation because there is a lot to know to get started with unix; it would be difficult to explain it all in a chat room. What's more, most of the regulars in those chat rooms have seen & answered the question enough times that they understandably do not look forward to doing so again.
So I'm answering that question here, once. If all goes well, when someone enters a chat room & asks how to start learning about unix, someone can point them to this article.
If you already know what unix is, or if you don't but you also don't enjoy reading about petty controversies about a definition, skip the ``What is Unix'' chapter & start reading Chapter 4 ``Some Basic Commands''.