You can export a text file containing all the keyboard shortcuts for InDesign (2.X or CS), and keep it as a handy reference on your computer or print it out to tack on your wall.

Just go to Edit->Keyboard Shortcuts, choose the Set you want to inspect, and click the Show Set button in the dialog box. Show Set creates a text file showing all the keyboard shortcuts in the set, organized the same way the dialog box organizes them (by menu/palette.

Even if you've never customized your shortcuts, It's a nice way to see at a glance which functions currently don't have a keyboard shortcut, and which key combinations are available to you to assign.

My most-used custom keyboard shortcut: Option-F, assigned to Fill With Placeholder Text (in the Type menu). Try it, you'll like it!