If you want great coaching, you should really try a windsurf camp with Cribby http://www.guycribb.com/
or Jem Hall http://www.boardseekermag.com/home.php
. I know that there are also some girls camps, which would probably be ideal for you.
Abouut the equipment... I thinnk you should get a big board to start, like a 155 litre GO, or a 150 litre JP x-cite ride. When you get comfortable with that, then get a smaller board like 100-110l.
You will need at least 2 sails, a 5.5 and a 6.5. The 6.5 will get you planing in lighter winds like 10 knots, but since you are so light you could be planing with a 5.5 really early. Which model? I think for women a HOT sails maui DIVA is great, but generally you should look for a light sail.
All the best and a windy 2007!