Your swimming speed is more confined by your skill level. You can be the world's strongest man/woman and get your ass handed to you by a 130lb kid with a little training in speed swimming. I would say if you want to get faster in the pool, you're better off just staying in the pool and swimming.

That said, if you just want to weight train because its healthy and you want to be stronger then great! I really don't think you stand to gain much as an endurance style athelete by weight training though. If you were a sprinter, the yes of course.

Just my 2 cents.

IronWorker

I think that you can probably gain some useable strength from working out, but I wouldn't be the one to coach you through that. Swimming/running/biking are pretty specific movements, and it would be good to consult someone that has a good understanding of what is needed. Maybe try hitting up a triathlon forum and ask that question? Bet you will get lots of useful info from them.

Not to say I want you to go away, but you are talking outside of my zone now.

You can definitely do strength training to help you with swimming and with your sport in general. I too wouldn't presume to coach you on that.

The biggest thing I can certainly point out is that when it comes to strength training for endurance events core strength, stability, and conditioning is job one. The better your core the more efficient your transfer of power to the limbs. The better your form and endurance can be.

I would recommend you go here where you will find sections with great info for endurance sports, swimming, and I there are triatholon articles as well. For 1 buck you get 14 days access. That should be plenty of time to gather a bunch of info. There are all sorts of other sources on the net...I think there is a triath magazine. And of course a triathlon forum like Andrew said makes a bunch of sense.

But yes, you can strength train to help you with all your sport.

Once you come up with methods and goals etc, we can prob help you with the specific strength stuff. Frankly I could figure out a lot of this for you but it would be better if you do the work :)