I have a bunch of recipes in metric (yes, unfortunately we yanks still work in English measurements, which are hard to scale up or down), and weights. A cup is .2366 ml according to this link (I couldn't find my conversion table):
http://www.worldwidemetric.com/metcal.htm
"Shortening" usually refers to vegetable shortening (also called all-purpose shortening), which is solid at room temperature, white and basically tasteless. You can usually substitute the same amount of lard or unsalted butter, but you'll get a different texture, as butter especially has a far lower melting point. Shortening is used to make a flakier pastry, and butter to make a moister and tenderer one. For a pie crust, I usually use a blend of the two.
Half and half is literally a blend of whole milk and light cream. It's sold as "half and half" in U.S. grocery stores. I put it in my coffee, as it's less rich than cream, but has more "body" than whole milk (less water and more butterfat). For a lot of recipes, you can probably just use whole milk, or if you prefer a richer taste, cream.
I'm a culinary student/geek, so I hope that was informative and not blabby! Please let us know if you need conversions or substitutions. obviously, these recipes are a little Yank-centric. Like I said, most of my bread recipes are in metric weights.
Cheers,
Amy