Since Facebook doesn't make it easy to delete your Facebook account, here is a quick guide on how to do it.
First, there is a difference between deactivating it and deleting it. Deactivating it simply pauses the account and isn't much different than not visiting Facebook for a while. All of you information is still stored on Facebook and the moment you log back in, your account is reactivated with all your info still in place.
Deleting your account actually removes your data. I have not deleted my account so I cannot guarantee exactly how it works. According to the Facebook Group How to permanently delete your facebook account "Your account will be deactivated for two weeks, and if you DO NOT LOG IN during that period, your account is permanently deleted."
Use this link wisely as it may actually delete your account and ALL info associated with it.