A masseuse is a female who provides a professional massage. The term for a male massage provider is masseur. The term masseuse has come under a bit of a cloud in the past few decades, since prostitutes often masquerade as masseuses, and most legitimate professional masseuses and masseurs today refer to themselves as massage therapists.
That said, choosing a masseuse or masseur is a very personal decision, and your first decision is probably the gender of the massage provider. Since, for a full table massage, you may be naked under a sheet, you may find that you prefer a therapist of the same gender as yourself. There are a number of different types of massage available, and if you know which type you are most interested in, this can help you narrow down your choice of masseuse or masseur. Not every masseuse is trained and qualified to give hot river stone massages or deep tissue massages, for example, so it's a good idea to do your research before choosing a massage therapist.
You may find masseuses offering so-called "seated massages" at establishments such as nail salons, new age or health food stores, or in a hotel, airport, or mall. These are a great introduction to massage therapy, since the client remains fully clothed. A seated massage usually takes place in a special massage chair, with a cushioned doughnut shaped pillow for your face and support for your arms. Of course, you won't get the full benefits of a laying-down table massage, but seated massages are an excellent way to reduce stress and loosen muscles tightened by desk- and computer-work. Often, the masseuse providing the seated massage also offers full massages at another location where she maintains a massage table and office facilities.
You often find a masseuse or masseur affiliated with a chiropractor's clinic or other alternative health provider such as an acupuncturist. Look for someone who advertises that they are a certified or licensed massage therapist. In the US, for example, most states require that a massage therapist be licensed or certified by the state, which requires a minimum number of educational training hours, often 500 or more. National certification is also available in the US, which requires passing an exam from the National Certification Board for Therapeutic Massage and Bodywork (NCBTMB).