Training for first Ironman

I'm in the process of formulating a training plan to train for Ironman C'oeur d'Alene in June 2009. I'll start training mid first quarter of 2009.

My long runs will fall on Saturdays and my long rides will fall on Sundays. My question is twofold: can I use bricks for each of these workouts, Sat - ride/run, Sun - swim/ride, and is it too much to do these bricks every weekend of training?

Although this is my first Ironman, I've done numerous half and full marathons and do many century rides a year. Swimming is my weak link. I've completed a sprint distance and plan to use an olympic and a 70.3 during training to guage fitness.

Thanks for your help, and any other advice you may have for a newbie Ironman and future Kona Champion/Pro  will be much appreciated!

Peter