How do I access the iTunes settings on an ipad

Hi. I don't know if this is an iTunes question, an iPad question or an application question! How do I get into my iTunes account settings on an iPad? I want to stop pandora from charging me every month pandoras web site tells me to change manage my subscriptions through itunes, but i cannot figure out how to do this on the ipad. I cant find a manage subscriptions selection at all...

Thanks!