1) Go to a kite shop and buy an instruction DVD (or get it in any other way you know

)
2) Start swimming every day while watching the DVD over and over again.
3) Buy a trainer kite (1m) and practice @ your local park or beach (Do not practice close to other beach users)
4) Now you are ready to start your course with an instructor.
5) After you passed your course its time to buy a 2nd hand kite, board and a new harness (I suggest helmet and vest as well but most people hate me for that)
6) You are addicted for the rest of your life.