general advice is common sense. Don't work with any model until you've seen their passport (which you should be doing to employ ANYONE in the UK for ANY job)
Keep 2 copies of it, also a 2nd form of ID is good.
make sure to publish a method to contact you on the homepage, ideally on every page (standard business law)
There was talk about "RTA" becoming obligatory. Basically, make an entrance page that clearly states its a porn site. Include no naked ladies on this page.
It's irrelevant cause which 14 yr old boy is gonna go "Well I googled for 'Pamela Anderson takes it in the shitter' but I appear to have stumbled across a porn page. Oh dear, let me click on 'exit' and go and read up on the bible...."
btw get a lawyer (well, use him for his free 30 mins then get a new one)