what next for a beginner

armed with my brand new pair of goggles, the knowledge i'd gained from this and other helpful sites, and not much more, i hit the pool for the first time just over two weeks ago. being a runner, i expected my endurance to cross over to swimming.....man was i wrong. i was totally winded after just one lenght (25 yards). i had to rest for quite a while before i was ready to go again. all the while, there's a 76 year old pluggin away in the lane next to me. i'm thinking, how in the world does he do that? two weeks later, i've discovered that even though the fitness gained in running doesn't cross over, the principles of endurance do. that is, large improvements can be acheived in the beginning. i can go for two laps (100 yards) non stop, and start back again without much rest. one question. i'm breathing after each stroke cycle now(right-left-breathe). should i try to increase the strokes between breaths next or add another lap, or both? tj