which triathlon programme?

Wow.  You have good running base, and some biking and no swimming.  That would likely require some customization.  Is your first race an oly or a sprint?

A few simple things to do is to get 'caught up' in swimming by picking a program corresponding to your first triathlon length, start the swimming part at a week you know you can do.  Just 'hold' the other two sports until the swim 'catches up', then follow the program from then on out in all 3 sports.

Can you manage through week one of the 12 week beginner sprint?  If so, try to go with that.  And if you don't want to do the 'spinning' or interval workouts for the bike, just do the minutes for the bike and run (it seems you can).

OR perhaps if you need a more basic or shorter swim program, you can do one of my 'minutes only' programs here that start off with very low minutes/meters: http://www.beginnertriathlete.com/cms/article-detail.asp?articleid=28 and follow some of the swimming articles on workouts: http://www.beginnertriathlete.com/cms/article-detail.asp?articleid=528 or even my super basic endurance builder at http://www.beginnertriathlete.com/cms/article-detail.asp?articleid=122 ...once you can do about 30minutes, you can transition to that 12 week sprint program with workout details...or just continue on with my 'minutes only' sprint programs.  If you do that, just maintain your current bike, run levels till the swim catches up.