Hi
I worked on a cruise ship for more than a year. The experience depends on the type of person you are. If you like having lots of people around all the time and don't mind noise, sharing a small cabin and strict rules, this is a very good way to see some parts of the world. I used to work as a videographer for Carnval Cruise Lines and my experience was pretty good. They are one of the better companies to work for. I have heard very scary stories of Disney Cruise Lines. Also try Royal Carribean. I think they are okay. These cruiselines recruit all year round and you can just go to their websites to find out more.
And enjoy the scenery!