Help with workout schedule....

Thought I would step out of the shadows and say "hi". My name is Chris and I live The Woodlands, Texas. I'm 32 and have reintroduced my body to physical activity after a 12 year hiatus. I have been doing a little running and cycling over the last few months and have seen some weight loss and other positive results. But I have just added swimming to my regimen last week and could really use some help in setting up my schedule. I did take a look at the programs listed here....but feel I need something a little different.

So if y'all could help that would be great.

So here are a few known variables:

--My stats are as follows: 6' 1" @ 225lbs. (I hope to drop at least 25 lbs by Oct 1st)

--My first Tri is Dave Scott's Texas Man Tri on October 10th. It involves a 500M swim (open water)/18.5 mile bike/5K run.

--Time in NOT an issue. I own my own company and work from home so I can make my own schedule. I will dedicate however many hours or days it takes.

--I have hired a swim coach and will be training with her on Sundays and Wednesdays in the A.M. But I will still need at least 2 other training sessions a week as it is my weakest sport.

--I would like to keep my runs to 2-3 sessions per week at this point. I am prone to shin splints and until I lose a few more pounds I'm not sure my legs can take more than that. I have been HR training the last 6 weeks and can go for 45 minutes to 1 hour at 60%-75% MHR. Half of these sessions are spent at a fast walk pace.

--Biking is my strength at this point. I have been doing 5-10 miles per session 3-4 times per week.

I would really appreciate any help you y'all could provide.

Chris