This is the main area on your screen: to the left is the Sidebar, to the right at the top is the Mode and Login panel and if you switch in Advanced mode you reveal the Top menu bar across the top.

The Desktop is the main space on your screen - where you open Tiddlers, the 'pages' within this document. A TiddlyManual is just a large collection of these 'notes' (pieces of 'MicroContent'), that can be used, and sorted, in many different ways.

As you open Tiddlers you will notice that their titles appear in the Currently Open list in the Sidebar. If you have clicked on Links to open those tiddlers then they will have opened at the bottom of your list - this is so that you do not lose the page you are currently reading. Instead of jumping from page to page, this way the reader selects and 'lines up' the "chapter" that she requires.

Each Tiddler has its own menu that allows you to edit it, close it, etc.

Each Tiddler also has a section that slides open called "Show references and info" - and this is important as it helps the reader place this material in a wider context ("How does THIS piece of information fit alongside all of THAT information?... and what related areas to this content might also be of interest and value to me.)