Preserve your floral stamps in an album, plastic box or sleeve. You don't want to damage them with clumsy handling or lose them while you are trying to identify them. Stamps can be very delicate.
Examine your stamps and determine whether you can identify the type of flowers depicted yourself. If you are an avid gardener, you might recognize peonies, chrysanthemums or lotuses, all flowers featured on Chinese stamps. If you're not a gardener, ask a friend who is to help you out.
Ask a friend or expert who can read Mandarin to tell you what your stamp says. Your stamp may state right on the image what the picture and date of production is, as well as whether it is commemorating a certain occasion.
Check out a stamp dealer's website, such as XABusiness or Michael Rogers Asian Philately. You might be able to find a match for your stamp and get a general idea of how rare or valuable it is.
Go to your local library and check out a catalogue of Chinese stamps. Luckily for you, China did not start producing stamps until 1878, so you won't have very many stamps that you need to look through. Compare the images on your stamp with the images in the catalogue until you find a match. If you can read the date or serial number on your stamp, you'll probably be able to find its match in the catalogue immediately.
Contact the China Stamp Society if you still can't seem to identify your floral stamp yourself. The China Stamp Society offers collectors a number of resources, including pricing guides and an "expertizing" identification service. They can even tell you if your stamp's a fake.