I have taken over the maintenance of a website I did not build. The owner wants me to add some custom fields to the ad space on the home page. I've figured out how to add the custom field, and how to place it into the template, but I have NO idea how to style it (position it, etc). He also wants me to change the appearance of an element that is already there.
Is there a tutorial or something that can help me find out where to define these things? I cannot figure this out for the life of me.