Well, you should ask somebody who is working in IT before sign off but never mind about that. I am also interested in IT and i put some research into that subject plus there are some people working in IT from this forum. One guy is on Disney.
He has a college degree and shore experience and he get the job, he said if you don't have college degree and no shore experience that you should have these certificates(CompTIA A+, N+, Server+, MCSA, CCENT, VCP5) but this is all a long shoot of course if there are candidates that have shore experience or worse ship experience. I was watching one add for IT on Costa for one week and already applied around 200 candidates for the job.
I think you should get also CCNA voice and some basic satellite certificates. Its easy to get if you have all above cert.
Good luck.