None, the point of volunteering is that your doing what you can for something you believe in. If you don't believe in it, get out of the way, someone else does. Gaining experience and using it as a jumping off point is perfectly fine, but volunteering for a cause you don't believe in, is poor taste. So, ask less about your own experience, ask more about the cause.

I do volunteer work for NAMI Mercer NJ. As long as you have some education most organizations will accept applications for volunteers. I recommend you try organizations, even public libraries who need adult volunteers.

Be willing.

We are a Cancer resource center. Some previous volunteer duties are helpful. But willing to learn what we do. A team player and various areas of interest.

There is a website-volunteermatch.org. Good luck with that.....

Have a passion for what you are volunteering for and everything else will fall into place.

show up and have fun

I don't think you need much! Show up and do you best. Volunteering is a great thing for your resume, and it's a wonderful thing to do!