It's one of the first things you hear when you step on campus as a freshman: get involved in student organizations as soon as you can.
However, a lot of people don't actually explain to you what "involved" means. Being involved doesn't mean merely paying the dues every semester. It means getting involved with the organization. This means showing up to meetings, participating in the organization's events, volunteering with other members, and helping the organization prosper on campus.
Too many times have I seen and heard people brag about how they pay their membership dues just to be able to put it on their resume. They have no plans to do anything else with the organization. This, to me, is incredibly sad and frustrating. People who are actively involved in the organization, especially executive members in leadership positions, are very dedicated to their organization and need help of the general members in order to make their organization grow. It's very disheartening to have, say, 50 new members come in every semester, and only 10 of them actually do something for the organization. The rest, in my opinion, are just deadweight. Student organizatons can be one of the best source of friends and new experiences on this campus.
In addition to having those experiences through your organization, you also get work experience, planning experience, etc. to help you when you finally apply for a job. You can tell your prospective employer everything you did for that organization and give them real-world examples of the kind of work you did.
Also, if you're one of those people who solely join organization just to put in down on your resume, you're going to be left high and dry when your prospective employer asks you specific questions about the organization and your work with it. You won't be able to answer any of it because you actually haven't been participating. Not only will you look like a liar, but you also won't look very dedicated or enthusiastic. Many of these organizations are pre-professional organizations that can help you develop skills you can use in your specific job area after graduation.
Make it easier on your fellow student members. Make it easier on your future employer. Make it easier to explain on your resume.
Get involved, actually involved, and stay involved.