Should I have my carpets Steam Cleaned or Dry cleaned?

If I am going to pay for a quality carpet clean, what should I receive?

What kinds of stains will be removed when I have my carpets cleaned?

How long does it take for my carpet to dry after cleaning?

How soon can I walk on my carpet after cleaning?

How much should I pay to have my carpets and upholstery cleaned?

How often should I clean my carpets?