Here's what I see:

• The lighting is fairly soft, and warm. My hunch is that the photographer used diffused natural lighting (such as sunlight through a curtain). You could achieve the same with a diffused strobe (ex: through an umbrella) and gels or white-balance tweaking though.
• Whatever the light source, it's coming from camera right, somewhat behind the model.
• The lack of deep shadows suggests lots of ambient light (relative to the key light), or a reflector/fill light. I'd guess the former; note that the background is pretty light too.
• It's reasonably noisy, so it was probably taken with a high ISO. (This depends a lot on the camera though.)
• The depth of field is quite small; note the difference in focus in the neck area of her blouse. That suggests a wide aperture.
• It's not very sharp, even in the areas that are in focus. I'd guess that the photographer did not use a very sharp lens. It may even be a point-and-shoot camera; the noise, lack of sharpness, and low resolution give me that feeling.
• It's a very mysterious, suggestive framing/cropping.

I don't think there's necessarily any fancy Photoshopping going on -- nothing obvious to me at least. Most of this you could achieve in-camera.

By "focusing on the lips", you probably mean that the rest of the photo is more blurred than her lips & face. This is achieved through a shallow depth of field. Getting that effect is a big topic, but the short version is to shoot with a wide aperture, longer focal length, and closer distance to the subject as possible. Actually focusing on the lips is just a matter of taking control of the camera's focusing system; once you do that, the shallow DoF makes everything else blurry.