What & what not should you post on your facebook account?

[mike2op]

I don't have a facebook or Twitter account & really don't want to create one but some places I visited on web requires you to give them your facebook account details or requires you to have a facebook account.

My question is what is the minimum info that I can get by with if I create a facebook account, especially regarding following.

(1) Do I need to give my real birthdate ? If yes any legal reasons ? Any legal penalties from facebook or someone else for giving a wrong birth date ?
(2) Do I need to post my own photo ?
(3) Once I create the facebook account, can I permanently delete everything that posted on my account & close it if I decide to do so in future ?

Thanks