Local chapters of professional societies are a great way to network and get engaged with your profession:
IEEE NJIT Student Chapter
ACM NJIT Student Chapter
Check out these professional organizations -- they are a great way to learn about what's going on in your chosen profession. Many have free or very low price student memberships -- take advantage of them while you can!
IEEE (Institution of Electrical and Electronics Engineers)
Association for Computing Machinery (ACM)
Electric Power Research Institute (EPRI)
Institution of Engineering and Technology (IET)
International Society for Optical Engineering (SPIE)
Library of Congress page on renewable energy organizations.