How to get overview of keyboard shortcuts from OS X?
I find the free app CheatSheet is a great way to show what shortcuts are available, Install it and it runs in the background, then just hold the ⌘ key down for a couple of seconds without choosing an operand to get a list of all active short cuts of the current application.



CheatSheet uses the Accessibility API to read the menus of the current application, but you need to turn on support for Assistive Devices to allow this - the app shows instructions how to do it.  Because of this, it can only show the shortcuts that are obvious, and it might not show shortcuts that are not displayed via your apps menu bars, but nevertheless it's a brilliant way to learn an apps common shortcuts - once y ou have held down the key to show the list, you can then continue to type in the shortcut you want, so it doesn't need any new workflow to use it effectively, just a pause if you are not sure what you want to use.