Hello Jenn,
The diving in the Turks is fantastic. You will not be disappointed. Lisa and I took our classes prior to traveling when we were there in 2004. We dove with Caicos Adventures and they were awsome!!! They do offer beginner courses that you can take when you get on the island, however I would recommend that you sign up before hand. Club med also offers scuba classes as well. you will always have the opportunity to dive with dive master.
My recommedation would be to get certifiied before you go to the island. Since you will only be there for a week, you will be limited to the amount of diving you can do. It would be a shame to get to the island, and only be able to dive for one day.
Most sports Chalets hold classes on a regular basis. you can also find out what is available at any of your local dive clubs.
Club med may also have a resort dive class. This is usually done in one day and then you can go and dive with an instructor, however you are very limited as to the depth of your dive I think it is 30 feet so you really will not be able to experience the reefs as well.
Lisa and I are going both weeks with Olivia so we can get the most of our diving while we are there. You are absolutely going to love the island!
I cannot wait!!!!
Feel free to contact me anytime if you have questions.
Heidi