After taking a Computer Course in High school, I felt extremely comfortable with my shortcut skills in Word. Learning the same shortcuts in Word 2007 was a very easy and enjoyable task. While slightly different in some areas, Word 2007 does an excellent job with shortcut keys and commands.
A great addition to the shortcut system is that in order to make all tabs and options available to you with shortcuts, a quick hit of the TAB key reveals all the shortcuts for all the tabs on the ribbon. This makes using shortcuts to find all tools and applications much easier in Word 2007.
A personal favorite shortcut which came in handy was the shortcut of "Print Screen" which copies a picture of the screen to clipboard. I had some trouble with my computer and the man helping me was able to do so much more for me after receiving the pictures of my screen.
Other very helpful shortcuts include the simple use of HOME, END, SHIFT-HOME/END, CONTROL=ARROW. All of these shortcuts make moving through your document much faster and efficient.
The other usual shortcuts such as Undo, Redo, Find, Replace, Bold, Underline, New Window are all still there and make Word 2007 easier to use.