The highlighted links below provide a wealth of information on competitive swimming:
The Race Club - Olympic Champion Gary Hall Sr provides a wealth of information on competitive swimming. Checkout the Multimedia section.
Swimming World Magazine - up to date information on the world of swimming. Checkout the "Morning Swim Show" under videos.
British Swimming - all you need to know about competitive aquatic sports in the UK.
Go Swim ! - an unlimited number of drills and workouts for all swimmers.