It helps you network, meet people, and have support for things in many cases (I was in the Student Nurses Association). It also looks great on a resume when you graduate and apply for jobs. It lets the employer know that you were active and involved while you were in school. I would definitely recommend being in some type of group for those reasons.
Oh my gosh Jennifer, I could talk to you all day about the importance of this! :) I was the kid that went to college with the mission to have fun and make friends and to join a club/group was certainly not on my agenda. I had fallen into an informational meeting for a Sales and Marketing organization on campus and fell in love with it! From that one decision to participate in that org. for 3 years, I had met many of my very best friends (to this day!), some incredible corporate contacts (they were my references for my first job!), and most importantly, REAL WORLD experience. There is a huge difference in presenting in a speech class than presenting to the CEO of Kodak (yes, that really happened, and I was SO anxious!). What did that do for me? I have zero fear of public speaking, I know the importance of a firm hand-shake... Just put yourself out there! You will grow SO much from it and look back and track a lot of your success back to your involvement. Go after it!
I was very involved on my campus. Kind of all over the place. From fraternity life and Student Government to orientation leading and our programming board. Something that every one of these organizations had in common that really helped me was the fact that you needed to keep your grades up in order to participate in any activities. Basically, if you wanted to do fun things with these organizations, you need to represent them well by being successful with your studies.
Participation can result in better grades. Also, it may help you know others in your classes and you can help each other rather than asking a stranger that's sitting near by. Good luck to you!
I admittedly wasn't part of many clubs in college. I worked full time in addition to going to school full time, so I didn't have a ton of time for extra activities. With that said, I wish I would have set aside more time to join clubs. While it helps a little when applying for jobs after graduation, the main benefit is meeting new people and getting a chance to see if you have a real passion for whatever the group is. I was in an investment group in college, and it helped me realize I had a real passion for personal finance. While I didn't major in finance, I used a lot of principles from that club in my everyday life to help manage my money. I also made some great friends in the club as well.