Good choice to go OR for the dry suit.
I'm in my third dry winter now, here some tips that go for any brand dry suit:
> don't overdo it on the layers. OR sells a rather warm overall, for me that's too hot.
In temperatures of 5-10 °C I go with a thin jogging pant and thin ski-undergarment on top, sometimes with a cotton sweater. Don't wear cotton on your skin as you'll stink up your car afterwards.
When it's colder I start adding layers, ski undergarment pants and maybe an extra sweater.
Look at air temperature rather than water temperature, unless you're a beginner laying in the water all the time.
> Pull your ankle and wrist seals a few cm past the joint, to where the leg/arm is thinnest. Make sure you have high boots to go over the seals to avoid spray to enter your suit.
> Other tips:
- lube the zipper with zipper wax every two or three sessions, get it from OR or a dive shop
- try to avoid operating the zipper with sand in it
- squeeze out as much air as possible after you closed your zipper by squatting and lifting the neck seal. This will improve swimming a lot.
There's a very good donning video for the surf dry suit (it's a 2 layer version, still some very useful stuff in there for your Pyro), http://www.youtube.com/watch?v=utM7NbRGF9k
and the manual that came with your suit can be found here:
If you have more questions feel free to post them here or on the OR forum. Enjoy the dry ride!