Your post suggests, jana08, that you've never done this sort of work before. If this is the case, my advice would be don't do it. Get some training.
Upholstery cleaning hides more potential problems than carpets. You need an upholstery tool for rinse/extraction as a normal hand tool is totally unsuitable. You need to be able to recognise fabric and construction, fibres, fillings etc. etc. and know their characteristics and problems that arise. Why do you think there are still a good number of CC's who don't clean upholstery? There's a disaster waiting to happen somewhere.
SAFE and happy cleaning
Ken