To see who has visited your profile is a 2 step process.
1) Go to "My settings" on the lower main menu and click "My privacy options" and make sure that you check "Yes, display users who viewed my profile." And click the save changes button at the bottom.
2) Go to the "What's new" tab on the lower main menu (under the "Home" button. On the "what's New" page, in the upper right, you need to click, "who viewed my profile." That should do it.
There is one thing though that all members must understand. You will only see who has viewed your profile from the moment you changed your privacy option.