There are literally hundreds of keyboard shortcuts. I've included the most important ones in a partial list. Trust meyou'll like using them, and soon, using them instead of using the mouse will feel quite naturaljust like riding a bike or learning to type.
Keep in mind that this list is of the default keyboard shortcuts. There's nothing wrong with mapping your own, but the default ones were carefully planned to be ergonomic and logical, so that's what is listed here.
Using these shortcuts will speed you along and save your wrist from repetitive strain using the mouse. If you find yourself using a menu command a lot, look at the menu to learn this command's keyboard shortcut. Most menu commands have keyboard shortcut equivalents.
If you want more, there are more! Just press Opt+H to see the default shortcuts. You'll be amazed at how many default shortcuts there are and how many more shortcuts you can map to the keyboard. In Chapter 4, "Organization and Basic Editing," see the section "Mapping the Keyboard" for instructions on how to do this.
The shortcuts in bold are the first ones to learn, because you'll use them almost every time you do any sort of project, and they will really speed you up.