How to delete your Facebook account
(Source Facebook.com) If you deactivate your account, your profile disappears from the Facebook service immediately. People on Facebook won't be able to search for you, though some info, like messages you sent, may still be visible to others. We also save your profile information (ex: friends, photos, interests) in case you want to come back.
If you don't think you'll use Facebook again, you can request to have your account permanently deleted. Please keep in mind that you won't be able to reactivate your account or retrieve anything you've added. Before you do this, you may want to download a copy of your info from Facebook. Then, if you'd like your account permanently deleted with no option for recovery, log into your account and let us know.
If you can't log in to your account, you'll need to reset your password first. To do this, go to www.facebook.com and click the Forgot your password? link below the password field. Once you’ve followed the instructions to reset your password and can log into your account, you can deactivate or delete your account using the steps outlined above.