CC is left over from the days when you would send a carbon copy of a document to someone else, today its often known as that but may also be known as a courtusy copy.
To use the CC field just add in other addresses you want the mail to go to. The To: field should be the main recipient.
BCC is the same idea, but the B is for blind. This means that the person who gets the email doesn't know who else it was sent to. The best way to do this is to put your address in the To: field and then all the people you want to send the email to in the BCC field. This is the best way to send out a newsletter, for example, as the recipents don't collect email addresses. This is something so many companies overlook and is bad practice.
As for CCi...haven't a clue, shouldn't read French womens mags!