First, log into your account. Second, find the person you would like to add as a friend. There are two ways to do this. Either find a post that they made in a thread, or find them under the Community tab (located at the top of the page, right next to "forum."
If you're doing the former, simply click on the "Add Friend" button, located on the left-hand side of the post, under their username and avatar.
If you're doing the latter, click on the "Community" button.
Then either type in their user name (in whole or in part), or find them by gender, national origin, or both.
Once you've found the person, click on their user name to enter their profile. Once there, just click on the Add Friend button, located just below their avatar. From there, you're done. It is now up to the other person to accept or decline your invitation.
If someone offered to be your friend, the process is even simpler. Simply go to "My Friends" on your Quick Links, and click on the "Pending Friends Request" panel.
Click on the box next to the person, and then click on either the Accept or Decline button.
You will know that someone has sent you a friend request becausethere will be a notification in orange in the upper-left hand corner of your screen, just to the right of the Control Panel.
If you ever decide to drop a friend, just go to My Friends, click the box next to his or her name, scroll all the way to the bottom, and click "Delete Selected Friends."