Look under accounts
There are two options, deactivate which means it still exist but anyone contacting you via facebook will get a message that your account has been deactivated.
Second is to delete. It is complicated but they do give you the option. Warning. It takes 14 days to become official. If you sign in before the 14 day are up, the account is put back into service (I think this is to keep your friends from hacking into your account and deleting it)
I recently deactivated my account (after removing all my notes, photos and comments). I have not decided if I am going to make it permanent or not.
I will admit I missed it for a day or two but now not so much.
I actually have a love/hate relationship with Facebook. At times, I just want to delete my account and never venture there again. Other aspects I find useful. As a sailor in the Navy, I move around a lot and FB is a good way for old friends to keep in touch. I also, surprisingly, use it for work. People check their FB more than their email and nobody checks their work email on weekends. When I'm at sea and need something from a co-worker back on the beach, the quickest way to get a response is to send them a FB message.
What I really need to do is nuke my friends list down to only true friends and family members and certain co-workers. This would make FB a lot more tolerable.