According to most carpet manufacturers you should have your carpets professionally cleaned at least every 18 months to extend their life and good looks. Most homeowners, however, wait until their carpets are soiled and stained before calling in professional carpet cleaners. If you fall into the latter category, you might have some questions as to which service to call, how to prepare for a carpet cleaning, and what to expect when your cleaning company arrives.
Who You Gonna Call?
There's really no set answer to this question. There are tons of carpet cleaners out there, so the main thing to inquire about is what method the company uses and which type of equipment they have to get the job done. And, of course, be sure to ask for (and check!) references before you make a decision. A long list of satisfied customers usually means the company does good work. If they hesitate to provide you with names, however, choose someone else.
Accepted Methods
There are five different carpet cleaning methods commonly used by professional carpet cleaners. Steam cleaning is generally considered the best method around, providing the deepest clean, but there are benefits and drawbacks to others as well. Dry extraction methods mean quicker drying times, and rotary methods work well when performed by a trained professional (though they can do serious damage in the hands of someone who doesn't know what they're doing). The most important factor is that the carpet-cleaners you hire are trained and experienced in the proper operating procedures for whichever method they use.
Manufacturers Know Their Carpets
Finally, be sure to check the recommendations given by your carpet manufacturer for cleaning your carpets and follow them. Using a different cleaning method than they suggest can void warranties, leaving you stuck up that famous creek if anything goes wrong.
Make sure to get a regular cleaning! Use this link to
Clean Carpets
Prepping for Your Cleaner
Anytime you get carpets cleaned, there are a few important procedures to follow. First of all, you're going to need remove furniture from the areas that need to be cleaned. Second, be sure and vacuum the floor before the carpet-cleaners arrive. Doing both will save you bundles over having the carpet-cleaners do the prep for you.
After the Fact
After your carpet cleaning the main thing is ventilate your home and dry out the carpet as soon as possible. Set up floor fans and turn on ceiling fans if you've got them, and never let a floor take longer than 12 hours to dry out. Also, don't walk on, or put your furniture back on carpet that isn't completely dry. Other than that, all that's left to do is enjoy your beautiful, clean carpet, and mark the calendar so you don't forget to schedule an annual cleaning for next year as well. 
Matt Goering, formerly a carpenter and house painter, is a freelance writer for the home improvement industry who has published over 600 articles.