Public Printing Community Centers

Me and my organization are looking at public computers and we have a good solution and plan however, I am looking for a good public printing solution. We are looking at 5 public computers per community center and we will need a way to charge for the printing usage and we wont be able to use something like pay pal because our clients will be mostly children. We would also want to monitor the printing so useless printing and waste of ink/toner does not occur. Does anyone have any suggestions of what can be used to monitor and charge for public printing we would also need something thats cost effective for the small locations we have. Thank You for any responses!