If you are following along in order, this is the first post you should read.
Welcome to OS X and your Mac Desktop. If you’ve never used a computer before or if you’ve never used a Mac, this post is going to give you a great overview of the pieces of the Mac OS X desktop. It covers some basic concepts and introduces a few terms that will be using over and over again. The entire tutorial should take you about 10 minutes to read through.
Behold, the Mac OS X Desktop in all it’s glory:

Behold! The Mac OS X Desktop
The desktop is broken into a number of sections. We will touch on each of them briefly here and give them deeper treatment in later articles.
Let’s start at the top of the screen.
The Apple Menu
The Apple Menu designated by the Apple symbol is a system wide menu and contains important menu items like Sleep, Restart and Shutdown. If you have your Mac setup for multiple users it also has a Logout Menu. The additional menu items we will touch on in later articles
The Menu Bar
Your interaction with your Mac is through running Applications When you surf the web, check email, view pictures, etc. you are using specific Applications. These applications are like obstinate children, they must be commanded before they will do anything. Commands are given through the use of application menus. When you are running an application, the commands for that application are always placed in the Menu Bar.
The commands are typically laid out in a logical structure so if you learn commands for one application, you will find similar commands for another application in the same place. Since you are currently reading this article on the Internet, you are probably looking at the Menu for Safari. Go ahead and click through some of the menu items. I’ll wait.
Menu Extras or Menulets
To the left of the Menu Bar is an area that holds Menu Extras or as they are affectionately known, “menulets”. Menulets provide quick access to common System Preferences items. They provide both a menu (click on one and you’ll see) and feedback (note the battery indicator in the screenshot). We’ll discuss these more in a later post.
Desktop
Below the menu area is the Mac Desktop. You can do all sorts of cool customizations to the desktop and we’ll get to those later. For now, know that the Desktop like a real desktop can hold things that you use frequently. In the screenshot above, our desktop contains an icon for a Mac Disk Drive. Keep in mind, you can drag any type of file or folder onto the desktop and if you’re not careful could end up with something like this desktop below.
The Dock
The Dock is the strip of icons at the bottom of your screen. The Dock is broken into two areas, the left side holds program icons, the right side holds everything else including folders and the trash can.
The program area of the dock provides you with one click shortcuts to open your favorite programs. You can add and remove programs to the dock by dragging the icons on and off the dock area.
The right side of the dock contains shortcuts to your Documents and Downloads folders. You can drag additional favorite folders into this area. It also houses the trash can where unneeded items go to die.
Summary
This is the end of our brief tour of the Mac OS X Desktop, additional articles will dive into each of these items in more detail.