However in most recent versions of OS X, Apple has stopped showing the Library when you navigate normally using Finder, instead you will have to use the "Go to Folder..." option on the Finder menu bar.
1. Open the Finder
2. Go to the Menu Bar and open the "Go" menu.
3. .Select "Go to Folder..."
4. Enter the following path: ~/Library/Application Support
There's an alternative, easier way. Open the Finder, then browse the menu bar to the "Go" menu. On your keyboard hold the Option key. The Library folder will show up there.
