Where do I find the "Application Support" folder on my Mac?

Here's the issue, I am currently trying to intall a mod for a video game I run on my Macbook Pro through the Steam App. The game is called "KSP". I would need to open the software files contained within the game in order to install the mod. There are a lot of people online saying that this is where I should go to find the code files for my game:

/Macintosh HD/Users/[your_user_name]/Library/Application Support/Steam/SteamApps/common/KSP

The problem here is that when I go into my user folder, I do not see a "Library" folder under my [your_user_name] folder.

There is also a second possibility. Perhaps that information I recieved was wrong, and I am actually to search under these folders:

/Macintosh HD/Library/Application Support/Steam/SteamApps/common/KSP

But the issue here is that the "Steam" folder doesn't exist under the "Application Support" folder.

Am I missing somgthing here, or do these folders simply not exist? Was the SteamApp not correctly intalled? Any help would be greatly appreciated, thanks!

{I am currently running Lion 10.7.5}