not a pest control expert, but I battled the same thing in my house. What I can tell you from my experience is that there are a ton of resources out on the web that you can use. I purchased some stuff from www.doityourownpestcontrol.com. They have some information on the site as well.
Carpenter ants
One of the big problems with Carpenter ants is once they started building a nest inside your wall, they expand laterally. When you disturb the nest, the workers will grab the eggs and attempt to move them. You need to attack them in a pincers like movement, drilling into the wall cavities on both the left and right side of where you think the nest is, and "puffing" in a bunch of poison dust. This way when you hit the main nest, they will run right into your prepositioned poison. Oh, ya, and you want to put something down that will last for a while like a boric acid based treatment, Lowes and Home Depot have carpenter ant specific powder that works really well. The reason is, the carpenter ant eggs won't be affected by the poison, and if you don't have poison there to kill them as they hatch, you'll have another colony pop right back up.
One of the resources I read said that by the time you see your first carpenter ant inside the home, the colony has already reached several 1000. I committed giggling genocide on those filthy house destroying bastards, but the war isn't over! It's never over! There were coming out of the God Damned walls! Sorry, I have flashbacks sometimes...But anyways, I continue to do outdoor barrier treatments using a sprayer and a concentrate poison. I spray 2feet off the walls and 1 foot up the walls, all around the perimeter of the house. I then spray around all windows and doors, any penetrations like exhaust fans, electrical service entrance, and vents. I also spray a line up any corners, like where the chimney meets the wall, because I read that ants like to walk up corners. And I finished with a line of poison just below the flashing where my siding meets the brick. The goal is to make sure that any path into your home gives those bastards a dose of poison. Oh, another thing I remember, carpenter ants can actually jump/fall from over hanging trees onto your roof and get into your home. I don't have anything like that at my house, but as far as I'm concerned, as long as they can't get out to lead others into the home with out poisoning themselves, I'm not concerned.
Man, just remembered something else as well, it's not a bad thing to let them poisoned ants leave because they are cannibalistic and will recycle the dead into food for the colony. Once one of them brings the poison into the colony and dies, they will be fed to others and the colony will be hit hard. You can't kill all the carpenter ants in your area, but my goal is to make my home very unattractive to the little bastards...and if my neighbor's house looks like a better place to set up, well, they should be outside doing barrier treatments as well