Can't find the Google Chrome User Data Directory in Mac OSX Lion

Home/Library is a hidden folder on recent (10.7+) releases of OSX.

To get to the correct folder, do this:

• Open a new Finder window
• Press CommandShiftG
• Type in ~/Library/Application Support/Google/Chrome/Default

You are now in your profile directory. Click on the directory named User StyleSheets, and edit Custom.css to your heart's content!

Going to try converting @William-Jackson's comment into an answer.

Are you looking at: /Library/Application Support?
Or, are you looking at: /Users/*johnym*/Library/Application Support/Google.....?

The second one is where you should be able to find the user data directory.