Joining a professional association is a great way to build your resume. You will also make connections with others in your field and gain more knowledge about topic areas that interest you. This page lists a few prominent Accounting associations.
According to their website, "AICPA members represent many areas of practice, including business and industry, public practice, government, education and consulting. The AICPA sets ethical standards for the profession and U.S. auditing standards for audits of private companies, nonprofit organizations, federal, state and local governments."
Since 1919, the IMA has worked to "promote knowledge and professionalism among cost accountants and foster a wider understanding of the role of cost accounting in management."
The IIA provides guidance on the IPPF standards, and research and reports on Internal auditing. They also provide study resources for Internal Audit Practitioner, CIA (Certified Internal Auditor, and CRMA (Certification in Risk Management Assurance) certifications.