Professional associations provide many services: conferences, communications, networking, and information. These are all opportunities to for scholarship and research, and can help students and researchers go further in their careers.
How to browse through these organizations:
It is not necessary to join every professional organization, but it might be useful to join at least one. Try to find a good fit: what comes with the membership dues? Do they have a publication, or a conference? How long has it been around? What is the mission statement of this organization?