You've picked a great area to build up experience. You can experience a wide range of conditions here without having to travel very far.
You might consider checking out the Barnet Sailing Coop
. A friend of mine is a member as has given it some good reviews.
Experience on a variety of boats is the most important thing. Aside from the Coop, look into local racing as it's possible to be a volunteer crew, and you will learn a lot and learn fast.