Speaking as somebody who has been involved in the recruitment of new staff in both my past life and my dive life (although not for my current centre), and somebody who has put in dive job applications based only on CV, I can say the folllowing.
If you are required to provide a CV for a job application - all that stuff about "people would say my greatest weakness is that I work too hard" is rubbish, get rid of it. They want to know who you are, what makes you tick and what your experience is, even if it's not much.
Depending on the job, your years of experience may not be important; many dive centres will take a chance on an inexperienced instructor in the hope they will be good at it and then become experienced instructors themselves - as long as you're honest about it. If you feel you must put your certification history then put "Open Water (or whatever), Feb 2005, DM March 2006, Instructor October 2006" or something. Put your current certification level under your name: ie:
Quentin J. Instructor
PADI IDCS - 783493
Now your employer knows when you started, when you decided to become a pro, when you became an instructor and we already know your current certification level. They are really not going to be interested in when you passed every specialty course that you took. I have seen a few CVs which list every single dive course the applicant ever took!! Makes you look silly.
Specialties can be important so list all courses that you are capable of teaching.
In many resort areas, languages are the key. Important to be honest with your ability here - if you can't teach in it then it's nice to know you speak a little french or japanese or whatever, but if they need a fluent language speaker and over-exaggerate on the CV, then you are going to be in trouble when you turn up for work!
If you don't have much dive instructor experience, or none, then prior experience from jobs that is relevant would include supervisory skills, sales of course, customer-facing jobs of any level that require a modicum of personality and/or authority to be successful. Any water based activity including boat handling is good - plenty of jobs require you to have a professional license.
But there are thousands of instructors out there who can whip up a good CV and have the necessary qualifications. Make it easy to read, cut out the male cow-poop and put in what's relevant to a job where you are required to both educate and entertain whilst maintaining control of your customers!
A photo is essential in many locations - I put mine in by default because I don't want to work for a company that won't hire me based on appearance, so I'd rather they cut me out with a photo before I waste my time with them. I also think it adds a personal touch. For many places however, there is no substitute for putting in a personal appearance at the dive centre for which you wish to work.
Hope that helps a bit - any other specific questions please feel free to ask.
Cheers
C.