Check out this guy's site:
Work On Board Cruise Ships | Wandering Earl
While I was always quite skeptical of the online e-books, I took a chance on this one and overall I think it is worth it. There are resume examples, cover letters, info about the different lines, job descriptions, salary ranges, and more. But even more valuable is Earl's willingness to email with you and his very valuable advice.
I'm not at all related or invested in his project, but I think it's worth mentioning here that it is quite valuable.