I’ve been using the prerelease versions and have found a few tips that are worth mentioning.
Learn shell: There are a lot of quick tips and shortcuts that make using shell even nicer. It’s worth taking a couple minutes to peruse the shell cheat sheet. It’s worth knowing that alt-tab works as expected (even across workspaces) and alt-` (or whatever the key is on your keyboard above tab) will cycle through windows of the current app. There are many other useful tidbits on the cheet sheet page.
Remap keys: In the control center, choose regions and language, select the layouts tab, and then click the options… button. A dialog will pop up. On my ThinkPad, the meta key (the one with a little Windows logo on it) is a bit small, so I remapped capslock to an “additional super” (which makes it switch into gnome-shell’s overview mode). Be sure to also set a compose key here (such as your right alt, for instance) too, for compose key goodness.
(Update: Remapping keys has since been moved to System Settings → Region and Language → Layouts → Options… → Compose key position → [select the key(s) you want for compose key])
(Update 2: Remapping keys in GNOME 3.6+ has since been moved to System Settings → Keyboard → Shortcuts → Typing → Compose key → [click and hold, and select the key you want for compose key from the dropdown])
Customize keyboard shortcuts: From the control center’s main view, select keyboard and then switch to the shortcuts tab. Here, you will find many actions that are available for mapping to your heart’s content. For instance, I map launching a terminal to F1 (because I’m a computer geek, and Trae McCombs got me hooked on that key shortcut years ago). I also remapped the shell action key plus a few keys for various window and desktop commands. You can do this too, as the shell overview mode only activates when you let go of the key, so if you do press the window key and some other key(s), then that keyboard shortcut will take precidence. For instance, I have it set so that the Windows/capslock (see above for key remapping) key on my laptop plus an arrow will switch the workspaces. (Normally, this is control+alt+up and control+alt+down. On my laptop, I can hit capslock+up and capslock+down. It’s a little easier to hit, given my keyboard.) I also have the same keyboard shortcut with the addition of shift for moving windows across workspaces. In addition, my computer is configured to do other window management with the super key (the win/capslock key) plus others. Super+m is maximize, super+v is maximize vertically, super+h is maximize horizontally, super+w is close window, super+f is fullscreen (which is great for Firefox, if you want it fullscreen with the tabs visible, versus its built-in fullscreen which is fullscreen for the content), etc.
Simply type & search: Once you’re in overview mode, you can immediately start typing and search will match apps. You can also hit down to cycle through matches and hit enter for the selected match. (Hitting enter will launch the top-left app match by default.) It’s also worth noting that there are buttons to perform Wikipedia and Google searches (on the web) at the bottom of every search.
Alt-F2 “run” dialog: If you’d like to quickly run a program and know the name you’d type in a terminal, hit alt-F2 and type. While the dialog looks very simple, it actually supports tab completion. The cheat sheet (mentioned above) lists a few additional hidden commands, such as “r”, which restarts gnome-shell.
Immediate app-to-workspace: If you middle-click (scroll wheel button) an app on the dash (the dock thing on the left), the application will open in its very own (new) workspace. This also works for apps in the application view and in search.
Switch to app across workspaces: When you switch apps via alt-tab or by clicking an icon of a running application in the dash, if the application resides on another workspace, you will be whisked to where the app resides.
Alt-tab with the mouse: While holding alt-tab (or hitting alt-tab and holding down alt after letting go of tab), you can select applications with your mouse. Of course, you could keep pressing tab while holding down alt to cycle through applications and windows.
Drag to the side or top: If you drag a window to the side of the screen, it will snap to fill half the screen. This is useful if you want to work on two things at once (such as referencing one document and typing in another window). If you drag to the top of the screen, it will maximize the window. If you drag away (after the window has been maximized), it will restore its previous size.
Anyway, these have been things I have found to be useful while using GNOME 3. You can download a live image for a CD or USB stick and try it even without installing. (You can also install; I know that the openSUSE version has a live installer — it’s how I installed GNOME 3 on my laptop. Just search for “live” in the overview mode and you should see it.)
Enjoy GNOME 3, and many congratulations to everyone involved!