The home folder is the one that's created when you create your account. So your home folder is billhower. All of your documents and settings are kept here, quite separated from any other users' stuff. Each time a user account is created, a new home folder is created for that user's files and preferences. Often when someone is writing out a file path, they'll use ~ (tilde) in place of the home folder like this:
~/library/keychains/login.keychain.
In your case, ~ represents billhower, your home folder. This is to distinguish from the system Library folder that's in Macintosh HD. In that case, it would be written out as Macintosh HD/library/keychains (or what have you).
However, it will probably be easier for you if you simply type "Keychain Access" in the Spotlight search at the far right in your top menu bar. (It looks like a little magnifying glass.) In fact, if you just start typing it in Spotlight, it will instantly appear in the list of results. Just click on it when it comes up in the list.
Hint: You can automatically bring up the Spotlight search box by pressing Command-Spacebar. Press Command-Spacebar again to hide the search box.
