Facebook privacy settings offer several different levels of privacy that vary from no privacy at all to being hidden from anyone, including your friends. If you attempt to view someone's profile without being friends with him, you can be successful only if the person is using a low level of security.
Open the person's profile in a web browser. If no security is in place on the profile, you'll be able to see all of the information displayed. You do not need to be logged into Facebook for this method to work.
Log in to your own Facebook profile. Navigate to the person's profile to see if you have any mutual friends. If you have mutual friends, go to their Walls and check their profiles for accessibility. The "Friends of Friends" privacy setting allows you to see friends of your friends.
Send a friend request to the person. This is the only way you can see his profile if he has "Friends Only" privacy enabled on his account.