When you first turn on the Mac, an Apple logo greets you, soon followed by an animated, rotating “Please wait” gear cursor—and then you’re in. No progress bar, no red tape.
Figure 2-1. Top: On Macs used by multiple people, this is one of the first things you see upon turning on the computer. Click your name. (If the list is long, you may have to swipe the trackpad to find your name—or just type its first few letters.) Inset: At this point, you’re asked to type in your password. Type it, and then click Log In (or press Return). If you type the wrong password, the box vibrates, in effect shaking its little dialog-box head, suggesting that you guess again.
What happens next depends on whether you’re the Mac’s sole proprietor or have to share it with other people in an office, school, or household.
If it’s your own Mac, and you’ve already been through the Mac OS X setup process described in Appendix A, no big deal. You arrive at the Mac OS X desktop.
If it’s a shared Mac, you may encounter the login screen shown in Figure 2-1. It’s like a portrait gallery, set against a handsome piece of dark gray linen. Click your icon.
If the Mac asks for your password, type it and then click Log In (or press Return). You arrive at the desktop.
Note
The very first time you run Lion, you get a huge “Scrolling in Lion” warning window. It’s Apple’s attempt to draw your attention to the new, drag-up-to-scroll-up behavior of a fresh Lion installation; clearly, the company correctly anticipated that this reversal of scrolling direction would freak out an awful lot of baffled customers. For details on this whole reversed-scrolling business (and how to turn it off), see Figure 4.
Chapter 13 offers much more on this business of user accounts and logging in.
The desktop is the shimmering, three-dimensional Mac OS X landscape shown in Figure 2-2. On a new Mac, it’s covered by a photo of a spectacular spiral galaxy; if you lean forward and squint, you might just be able to make out Apple’s headquarters.
Most of the objects on your screen are nothing more than updated versions of elements you already know from Windows. Here’s a quick tour.
In Windows, disk icons remain safely caged in the My Computer window; they don’t appear on the desktop automatically. The Mac starts out the same way; to find the icons of disks you’ve inserted, you have to look in the Sidebar (Up to Speed: All My Files) or the Computer window (Go→Computer).
If you’d like to save yourself that burrowing, though, you can choose Finder→Preferences, click General, and turn on the checkboxes of the disks whose icons you want on the desktop: hard disks, external disks, iPods, and so on.
This row of translucent, almost photographic icons is a launcher for the programs, files, folders, and disks you use often—and an indicator to let you know which programs are already open. They rest on what appears to be a polished, highly reflective shelf.
Because the Dock is such a critical component of Mac OS X, Apple has decked it out with enough customization controls to keep you busy experimenting for months. You can change its size, move it to the sides of your screen, hide it entirely, and so on. The Quick Look Slideshow begins a complete discussion of using and understanding the Dock.
The 
menu at the top left of the screen houses
important Mac-wide commands like Sleep, Restart, and Shut Down. In
a sense, it’s like the Start menu on a diet: It lists recent
programs, system-wide functions, and includes a quick way to jump
to System Preferences.
Figure 2-2. The Mac OS X landscape looks like a more futuristic version of the operating systems you know and love. This is just a starting point, however. You can dress it up with a different background picture, adjust your windows in a million ways, and, of course, fill the Dock with only the programs, disks, folders, and files you need.
The first menu in every program, in boldface, tells you at a glance what program you’re in. The commands in this Application menu include About (which tells you what version of the program you’re using), Preferences, Quit, and others like Hide Others and Show All (which help you control window clutter, as described in Tip).
The File and Edit menus come next, exactly as in Windows. The last menu is almost always Help. It opens a miniature Web browser that lets you search the online Mac help files for explanatory text.