...although Liberty won't be biggest for long. RCI's Freedom of the Seas has been launched and goes into service in June around the Carribean. I'm going on her in January next year. If you want a lot of info on different types of ships and cruise lines go to
http://www.cruisecritic.com/ . There is loads of info there.We book most of our cruises through Airmiles as you can normally get them a bit cheaper than going direct, but you can find loads of cruise booking websites, or try your local travel agent. It just depends how much time you want to spend 'organising'. If you can, go for 2 weeks, as this works out effectively cheaper as the airfare is always the same. Several cruise lines offer 'back to back' cruises, as most ships alternate between 2 routes (eg East and West Carribean), so you can go on 2 different itineries, but check as some stay on the same route every week. The wife and I love cruising as you only have to unpack once as the whole 'hotel' moves. You can do as little or as much as you like, there is no pressure to 'join in'. Hope it all goes well and you have a great time.