No! Unless you need the money, charging for tutoring just causes unnecessary problems. If you're charging students for your services, they expect nothing but perfection from you. Most people considering volunteer tutoring don't have the time and expertise to be all things for all people. The focus is on doing the best you can to help people within the limits of your (and the student's) abilities. Here are some of my reasons for free tutoring:
Paid tutoring raises students' expectations. I know this seems like a bad reason when you're supposed to be trying to help someone. What I mean here though, is that you don't put unnecessary pressure on yourself to do everything right. I feel much more nervous about helping somebody with their work when I know they are paying me for my services. Any slip-up would make me feel incredibly guilty about my performance. As a volunteer tutor, I can work in a much more relaxed atmosphere, and usually this results in a more successful tutoring environment.
Unnecessary burden on the students. Some students simply can not afford any amount for tutoring, no matter how small. These students may fail out before they are willing to exchange their next meal for some Calculus help. You can't fault them for that. But why does this need to happen? Free tutoring can help these students work through rough times and obtain the help and priviledges that the more wealthy students enjoy.
Who carries cash? If you're going to charge $2 or something for a tutoring session, what will you do if they don't bring their $2? Send them home? Ask them to pay next time? Seems like a waste of time to me.
You won't count on the money for survival. If you're really strapped for cash, and won't make it through the term without some income, tutoring can be a poor employment choice. You never know how many calls you're going to get, or how many hours you'll actually be working during the term. If you start to depend on money from tutoring and then the calls stop pouring in, you could find yourself if a tough position later in the term.
People are (generally) good. Very few people will abuse your offer for free help. Most people recognize the service your providing and are amazed that you'll help them for free. I often get students offering to buy me lunch, or a coffee, or whatever. I never accept, but feel free if you're comfortable with this. Just don't get to the point where you expect this - then you're basically a paid tutor.
Tutoring provides you with a great opportunity to help and meet other students. Why should you charge for something that provides so much in return already?
Any other reasons why free tutoring is better than paid tutoring? Tell me about them!