When considering the swimming school that you plan to enroll into, find out what they offer to you in the way of a variety of courses. Chances are they have a variety of different programs available to you so that you can definitely improve your skills throughout.
Some of the best swimming lessons are those that are taught to you individually. You will find that when you are working with people as a group, you wont get as much individual attention as you will with a personal trainer. It may cost more but is well worth it.