As a Canadian, I get exposed to both the British and American influences.
American biscuits are similar to British scones - they are a bready thing with the leavening agent being baking powder. Biscuits tend to be plain or savoury while scones tend to be sweeter, from my understanding.
Crumpets are another bready like breakfast or tea food. The ones I get here aren't cut, like an English muffin would be. They have all these holes on the top of them so when you toast them and then butter them, the holes fill up with melted butter. Yum!
Canada is supposedly metric but still uses Imperial (or British) measurements for some things. 1 cup is 8 ounces, roughly equivalent to 250 mL. 1 pound is 16 ounces, equivalent to 454 g. An American quart is 32 ounces but an Imperial quart is 40 ounces. 32 ounces is roughly 1 L but 40 ounces is 1.14 L. Temperature wise, the US uses the Farenheit scale and Canada uses the Celcius scale, with a lot of us having a good idea what the equivalent Farenheit value is.
If you can get a pumpkin in Britain, pumpkin pie is really good. It is more of a custard, at least the way I make it. Cooked, pureed pumpkin with condensed milk, eggs, brown sugar and a bunch of spices - I use cinammon, ginger, nutmeg. A friend of my mother's had a daughter who was engaged to a Brit. Who insisted there was no way he was eating pumpkin. So when he was over, she made two pies for Thanksgiving - a banana custard and a 'spice' custard. He chose the spice. And enjoyed it thoroughly, even after it was revealed that he'd eaten his first pumpkin pie.
North American marshmellows are soft, white things, about the size of a golf ball, and are just sugar and geletin, mostly. There is usually no flavouring to them. I understand that British marshmellows tend to be of a harder consistancy and are shaped and flavoured?
For recipes calling for lard or shortening, in most cases, you can just swap them one for the other. 'Pure' shortening looks very similar to lard but is made from vegetable sources. There is some talk that the lard is actually better for you because shortening is made from hydrogenated oils. I use lard for pastry, shortening for making cake decorating icing and generally use butter, margarine or oil in other recipes.
I don't make my own mincemeat; we buy it, usually jarred. It is mostly sweet. The commercial stuff doesn't use meat, per se, but does generally use beef suet, or fat, in the mixture. It is mostly stewed fruit.
Currents are a dried fruit. They are little berries that are dried like raisins but they tend to be much smaller in size and, to my taste, a little bitter.