I partially agree with jasskat, most cats are really clean and seldom need a bath. However, there are some cats that do need a bath once in a while, specially the ones with long hair, and, personally, I don't believe there's anything wrong in bathing them. Having said that... I did have a really bad experience with a pet parlor when they cut my cat's nail. And besides that, most of the parlors are scared of cats and give them medication to calm them down, which I'm so against.

On bathing them at home, it's a little hard, but not impossible, yousri. I've only had to do it twice with my cats, though.

But you need to make sure of a few things. The most important one is to ensure that no water gets into the cat's ears or kitty will get an ear infection. Second, make sure you rinse the cat really well and do not leave shampoo/conditioner behind so kitty doesn't get a skin infection. And use a brush in one movement so the hair doesn't get tangled (if the cat has long hair). When it's time to dry kitty, be prepared. Some of them HATE hair dryers, they are really scared of them. One of my cats is a prime example, even if I'm drying my own hair the poor thing goes on hiding so scared he gets.

Oh, and don't forget to put your not so nice clothes on, as you'll get wet with the cat : )