Tell me where can I post my data (e - mail, twitter and others)?
That being said, if you wish, you can make your email visible to others when they consult your user profile. In order to do this, you need to go to Profile-> Account Related Settings, and under the provided email, uncheck the “Hide email address from public?” Option.
In addition, in the “Forum Profile Information” section of your profile you can add some social account data (AOL Instant Messenger nickname, MSN Messenger email address, Yahoo Instant Messenger nickname).
There is no predefined field for Twitter and/or Facebook. These I guess you can add to your signature and/or personal text, although the latter is a very small field (50 characters or so). Nevertheless, you will not be able to do this until you become at least a Jr. Member (30 activity and >= 1 merit), or acquire a copper membership.
In any case, I would refrain as much as possible from providing real data that relates to you as much as possible for privacy and security purposes.