Anthropology is taught at this level in some of Québec's CEGEPS (= roughly sixth form colleges), including at least one English-speaking one (Dawson College, Montréal) and even in some Canadian high schools, as I found out from my students. I'm teaching a large first-year Intro to Anthropology in a Canadian university and, knowing the British education system (of which I am a product, of probably the same vintage as you) I'm sure that many of my students would have the same level of skills and knowledge as yours. So I'm kind of teaching at the same level. They are very much enjoying the introductory reader, 'Conformity and Conflict' (eds James Spradley and David McCurdy, Pearson Education - you can request a complimentary exam copy). Although this has some old classics, it also has a lot of recent articles which are either abridged from 'real' ethnographies or commissioned specially for this publication. It's well organized and offers a great deal of flexibility in what you might want to cover - altogether an excellent 'sampler' of ethnographies. It seems to me like probably the best value for money out of the Intro-level readers around. There is of course something of an American emphasis, but the range is broad.
As a full ethnography, we are getting our teeth into Bruce Knauft's intro-level book on The Gebusi (McGraw-Hill, 2010). This is just a lovely book, really nuanced, well-written and the great thing is that he did fieldwork in Papua New Guinea in 1980-82, 1998 and 2008, so you can discuss culture change and globalization rather than thinking of the exotic, timeless 'Other'. The first few chapters can be downloaded here.
I am teaching first year students in the Canadian Prairies and Horace Miner's ancient article (Body Ritual among the Nacirema, 1956 or so) works very well. Don't give away that it really is about the Americans and they won't notice that reading words backwards gives the text a totally new meaning ... easy read, short and crisp ... gruesome and fun. And about 'us' (sort of, I'm German but what the heck).