Great fish Lilith, there are a few things you should be aware of being a new tank , and if this is your first one. The site below has a great Q&A section, on everything from diseases to general care. I've had goldfish for years and I still go back to it for reference.

http://www.geocities.com/tokyo/4468/faq_health.html

Plus,

http://www.ponddoc.com/Topics/health.htm