There's usually always a small marquis in the main lobby of the ship announcing the days and times of the Friends of Bill W. meetings. It's also in the daily Carnival Capers newsletter, which will be delivered to your cabin each day. Enjoy your cruise!
I'm not sure about now, but I know 4/03 there were none of these types of meetings on the Pride. Perhaps you can ask a Social Host or the Cruise Director as you're walking in the door to board, they're usually there.
Wierd. Every ship I've been on for the last few years has always had Friends of Bill W. meetings. It's not heavily advertised, and you might have to look for it, but they were always announced in the ship's newsletter.