This is one of the most comprehensive Lightroom cheat sheets that I have ever seen.
The guys over at setup a blog today created this. Don’t let all these shortcuts overwhelm you. The best way to learn shortcuts is a few at a time and always the edits you make most frequently first. Another thing you can do is look for the shortcut in the drop down menus of Lightroom.
The image below is linked to a PDF you can print or save.