How do I add an Icon to my Action?

[Action("ActionName", "Action name", Id = 30115)] 

I have an action that shows as as a context menu when right clicking in the solution explorer. 
I want to add an icon next to the menu item (like several other menu items have. How can I do that?

I also have a menu item that shows up in the ReSharper drop down menu at the top of the app that I would also like to add an icon to. How do I do that as well?