Newts

I came across a couple of newts the other day whilst on a picnic near a Scottish reservoir. I couldn't identify them and even looking on the Internet found that none of the sites I had surfed had decent photographs of the 3 British species. Anyone out there recommend a site or book that has quality pics? One of them had a thin stripey line down its spine and a bright orange belly. I know they are protected I am just curious as to which species they were.