Took a few swimming lessons at my local baths about 6 years ago as I was sick of not being able to do more than one length front craw withouth feeling like I was drowning.

A few lessons and my front crawl had come on loads - they taught the same sort of technique as Total Immersion Swimmming, which I also bought a few years back when I was doing some triathlons.

The trick is definatelly to relax, it shouldn't feel like hard work, it really should feel effortless like you're gliding through the water BUT you definately need to think about it until it becomes habit. I used to swim a mile a day and that helped. You'll find once you've got the basics of the technique then you can really start to concentrate on improving the indivdiual elements.

I would say though that having a couple of lessons is really worth it (local pools don't cost much) as you may think you're not crossing your arms over or may think you're kicking properly but in fact you're not.

Good luck with it.