⌘ Command, ⌥ Option, ⌃ Control, ⇧ Shift, ↵ Return, ⌫ Delete, ⌦ Forward Delete, ⎋ Escape, ⇥ Tab. ⇧⇧ and Shift Shift mean pressing Shift twice; ⌃⌃ and Ctrl Ctrl mean pressing Control twice. Where two shortcuts are listed, either works.
Some shortcuts depend on where the focus is. For example ⌘N / Alt+Insert is Generate… in an editor and New in the Project tool window, and ⌘R / Ctrl+F5 reruns the selected configuration in the Run and Debug tool windows.