On Mac OS 10.7 and 10.8, the ~/Library folder [where your personal prefs are stored] is hidden. To open it, in the Finder, press the Option (Alt) key and in the menubar choose: Go > Library.
If you want to keep it visible, you can either use the terminal with something like chflags nohidden ~/Library/ or use a dedicated free application. You'll need to re-apply the trick with every system update (like 10.8.1 to 10.8.2, etc).
Let me know if it helps.