Do you have any good swim workouts?

I just started swimming for the first time in my life in November 08′.I can swim a 25 butterfly in 10.3 seconds, a 50 fly in 25 seconds, I swim a 50 freestyle in 26 seconds and a 100 free in less than a minute. however, I can’t swim either for distances…. do you know of any excercises to strengthen myself so that I will be able to do distances? In pool workouts?

Nice times! Especially the 50 fly. Here are the swim workouts I use offseason, girls season just ended so I will be starting these back up again. they really help with distance endurance but there are some sprints as well.