If you live in a big enough town you should be able to find an appropriate service in the yellow pages. If you cannot find one you may need to hire individuals, as opposed to a company, try putting an ad in the newspaper.
A way to find cleaning services is to go on line and look in your area by zip code. Things to look for in a cleaning company is if they charge more to come for emercency cleanings and how much. Also another thing to ask about is what kind of chemials they use it thier cleaning process.
Start by doing an online search for Apartment Building Cleaning Service. This should bring up choices of companies in your area, as well as general information on what you can expect such a service to do for you.