Just below your name in the log-in area after logging in there is a search window. Put his name in there and if he has posted anything on the site his comments will come up. Go into his latest comment and look for the letter on the upper left side of the screen or click his name above where his picture is on the left. This will take you to his profile, scroll down on left side you will see send message, add as friend and follow. All of these are links to that person through the profile.
Hope this helps.