By default, WordPress lets you input some of your contact information on your user profile page but what if, you want to have some more fields there. Well, it is not a difficult thing to accomplish if you want to have it. Just paste the following snippet to your theme’s functions.php file but remember when you add the snippet, you do edit lines 4 and 5 as per your requirements.
$user_contactmethods['twitter'] = 'Twitter Username';
$user_contactmethods['facebook'] = 'Facebook Username';
Snippet Source/Credit: TutsPlus