Forum Moderators: not2easy
Lots of websites have a boxed layout, you see it all over the web and nobody can really claim copyright on such a common way of organising a site. But if the navigation is unusual, say in a recognisable cartwheel shape, you might get into trouble for copying it.
Whatever you do, don't use anyone else's graphics without permission. Apart from that, it's difficult to answer this question without seeing the site, because so many sites use fairly similar layouts anyway.