If you want a sprinkler system installed, experts advise getting a contractor with a "C16" license for installing fire sprinklers. They are listed in the phone book under fire sprinklers or fire protection.
You may want to call the Contractors' State License Board at (916) 366-5153 to verify licenses and whether contractors are in good standing. Or check with your local fire department for information and recommendations.
Some manufacturers offer do-it-yourself kits, although fire officials say it's a good idea to have an expert check the plans and installation, especially if you aren't familiar with plumbing techniques.
You should also ask your building department for local requirements. Fire departments will usually check systems to see if they are working properly. Systems are checked with a test valve so the sprinkler heads don't activate.