If you intend to have your female cat spayed congratulations. You are not part of the problem of over-population - of mostly forgotten or unwanted cats left out near busy streets, catching diseases, producing more ill-fated kittens. People often get very excited with their new kittens and after the novelty wears off, they leave them out to fend for themselves - a sad fact.
Another good reason to have your female cat spayed, is that if she is not (and is an indoor cat) she will become very aggressive.
Spaying involves the veterinarian to surgically remove most of the ovaries (female's sex organs), fallopian tubes and uterus. Stitches are required, healing is quick.
Cats should get "fixed" before they mature sexually. Before 6 months is the desirable age for the operation. However, a cat of any age can be spayed safely. Following the operation, the hormone levels drop off gradually over a period of six weeks. These hormonal changes affect her behaviour which is evident after approximately one month - she calms down, becomes more affectionate, docile, and usually wants to have human companionship more often.