Is there a shortcut for setting labels in Finder?
Use ⌘+I when the folder is selected.
This will bring up the Get Info box. Once you expand the section General, it will be already be expanded the next time you trigger the info box.

I've searched &quot;MacOSX Hints&quot; for tips and found this which also refers to this:
With Lion you can add a toolbar icon to label a folder with just one click.