Many years ago I went to a swim camp to improve my swimming performance. They have come a long way since then, and you will find an incredible amount of information at their website, Total Immersion.

http://www.totalimmersion.net/

They offer clinics all around the country. They are not cheap, but there texts, videos, and you can even get a lot of instruction and see videos on their website if you have a fast connection. The founder, Terry Laughlin was practically the sole source of information for Fitness Swimmer magazine (sadly no longer being published.) Anyway, you will probably find many tips to become more streamlined in the water and improve your swimming.

No affiliation, and I haven't even tried to swim in about 4 yrs from fear of reinjuring a fragile rotator cuff.