I already knew how to look at html code on a lot of websites. You press right-click and then select "View Page Source". However, what I didn't realise, was that it's possible in many cases to view the CSS values too (eg how big the font is, what padding and/or margin is used etc.). This page explains different ways to view a website's CSS. The option I took was to use a firefox add-in provided by Chris Pederick at this address.