Base training

I just did my first tri a few weeks ago and essentially my race season is over with, but I am already planning next years races. Here is my question, I realized that I need to significantly need to build a better base in all three disciplines, but especially swim and run. I have basically 8 months until my first tri of 2010 and plan on using the next 4-5 months for nothing but base " mileage". I would also like to add in some strngth training as well as yoga and pilates. I feel I need to run and swim at least 2 times a week each, preferably 3 times but that doesn't leave much time for bike, strength, or flexibility while still allowing for rest days. Any suggestions how to structure a weekly program to get everything in while not overtraining. A little background as well. I am a stay at home dad during the day and work at the YMCA in the evenings so I basically can go to the gym to swim, run or "bike" during the day as well as run or bike after work when I get home. Thanks.