Magento

I am new to Magento and hopefully someone can help me out.
I am trying to change/add some fields in my “email order confirmation” page (ie. order_new.html).
I see many things like ....{{var order.getBillingAddress().format(’html’)}} .....and stuff and I am assuming it has something to do with my database since these things changes accordingly to the order and who ordered.
My question is since I would like to add other fields, both from seller and buyer, where are all these values? what kind of codes do i add?