Simply open the utility "Key Caps", in /Applications/Utilities .
It'll show you a picture of your keyboard. Then you can hold down option and see what characters are made, and same with shift and control and all the other modifier keys. Note that the white outlined keys when you hold down option are the accents. You option-click the key that creates the accent, and then you press the key that you want under the accent.
You can even have key caps change the font, to make sure the symbol you're looking for is in the correct font.