You can earn silver by posting (but not spamming the forums), doing quests, exploring with your pets in islands, selling and trading pets and items, and selling art. If you would like to know how to do any of these feel free to ask me in a pm or post here. It would take ages to make a guide on all of this (and I'm about to log-off, sorry!), so if you are looking for guidance in a particular area I will be more than happy to assist you. :)