I joined the American Massage Therapy Association while I was still in school studying to become a therapist. They have student rates, which are more than fair, and open you up to receiving the Massage Journal and also to resources on how to build and protect your career.
Their "Hands On" letters that come monthly are full of local information that you may need on upcoming events and happenings within the field in your area.
They also offer disability insurance through Marsh and Associates, which is a good touch. Also, your liability insurance premium is included in your membership fee every year so it's very nice to only have to think of one premium to pay a year.
They respond to questions and queries very quickly, and will help you in any way they can.