When you boot into the Gnome 3 desktop you get an empty screen. There are no icons on the desktop and no way to put icons on it at the present time.
|The empty Gnome 3 desktop on startup|
I guess the Gnome development team is planning to place widgets here in the future. In order to get productive work done, you have to go into the activities menu, either by (a) pressing the Windows key, (b) moving you mouse to the top right corner or the screen, or (c) by clicking the word activities on the top right of the screen. Doing this place you in the Windows view which gives you access to your launcher and work spaces.
|The "Windows" view|
I do not see the point of booting up into a screen which requires an additional key press to be useful. Since I pretty much use the web browser every time I boot my computer, one way to make Gnome 3 more useful at startup is to autostart the web browser.
To do this launch the application called Startup Applications and Add a new startup program. Just type in "Firefox" the box for name, "firefox" in the box for command and click "save". Next time you boot, Firefox will autostart so this is what you will see after the computer boots.