one pound of coffee is what exactly?

A pound af coffee is a pound of coffee wher I come from LOL A pound of coffee should yeild about 16 pots of good coffee in a home perk. Anotherwards 2oz per pot especially with flavoured coffee.
how much is an average pound of coffee?
It depends. Some roasters charge more other charge less. Some use good beans, other do. Some roast very well, other don't. You should go with what you like best, not how much per pound.

and how many cups of coffee is brewed from one pound?
It depends. According to SCAA, there are three catagories. 1) Gourmet, 3.5 to 4 ounces per 64 fluid ounces. 2) Classic, 2.5 to 3.5 ounces per 64 fluid ounces. 3) High Yield, 1.5 to 2.5 ounces per 64 fluid ounces. Also, your grind setting infleunces how much liquid actually is absorbed by the coffee grind. Work out a taste profile you like the best, then figure out how many cups you are getting per pound from that setting.

one pound of espresso blend makes how many shots of espresso?
It depends. Some people use 14 grams per double shot, other use a triple basket (21 grams) per double. Some people use single basket (7 grams) for single shot, but many shops don't use single basket. So, if all of your espresso are single shot, and you use a single basket, with no waste, mathematically, you can get 64 shots. But realistically speaking, it's more like 50 shots.