One of the best cheese tastings I ever did was 12 cheeses arranged from most mild to most strong. I don't remember if it was all one sort of cheese or not; I think it was. I just remember that by walking thought the different-but-related varieties I was able to really appreciate each one. Blue cheeses are spectacular for this, IMO. So much incredible variety. Sweet, sour, nutty, buttery, nutty. I'd recommend "flights" of related cheeses, to allow people to develop the taste for them. You could do a couple of different "sets", and then have some interesting varieties with tasty accompaniments. I'm thinking of this particular Bermuda onion cheddar, which is absolutely spectacular with pickles.