There are two types of goose fat: brown and blonde.
Brown fat is the fat that you get while roasting a goose; it renders off the goose as a by-product of the roasting.
Blonde (actually more white) fat is rendered in a saucepan.
Either kind is spreadable like butter, and has a smoke point of 375 F / 190 C.
“Goose fat solidifies between 16°C and 22°C and has a melting point between 25°C and 37°C.” 
In France, goose fat is sold in tins or jars (jars are more flexible for daily use as they can be re-sealed.) In some parts of France, everyday cooking is still based on goose fat in the way that other parts of Europe rely on butter or oil. It is particularly popular in the Aquitaine, Gascony and Périgord areas of France.
The perception, though, in the UK and in North America is that fats such as goose fats are for lower-end cooks, and that better cooks use oil. However, some English-speaking foodies are slowly discovering goosefat: in the UK, it has been imported from France since 1998, and is being sold in grocery stores such as Sainsbury’s.
Jews in northern Europe would use goose fat instead of pork lard; it used to be traditional to cook latkes in goose fat.
Goose Cracklings — some people like to also include small pieces of skin in with the fat, and cook them until dark brown and crispy and eat as a snack.
When you are cooking with goose fat, you need far less of it than you would an oil, because it doesn’t evaporate away or get absorbed into food as much as oil does. When people say that something cooked with goose fat was greasy, it’s because too much was used, and it tends to stay more on the surface of food items than be soaked in the way oil is.
Goose fat can be used as a spread on bread. Many people swear by goose fat for making roast potatoes with.
To render blonde goose fat: Remove loose fat from the raw goose. Put the fat in a small pot with an equal amount of water, and render over low heat. When it begins to sputter, remove the pan from the heat, pour the liquid into a bowl and let stand to cool. The water will separate off, leaving behind very white goose fat.
Duck fat, schmaltz, or another cooking fat or oil.
Goose fat is 57% monounsaturated fat, 28% saturated fat, 11% polyunsaturated.
Part of the “French Paradox” is that areas of the country that use the most goose and duck fat in their cooking have extremely low incidents of heart disease. 
Refrigerate in a sealed container for up to several months.
 The Goose Fat Information Service. Steventon, Oxfordshire. Retrieved July 2014 from http://www.goosefat.co.uk/page/usage-recipes
 As a final example, let us consider the French. Anyone who has eaten his way across France has observed that the French diet is just loaded with saturated fats in the form of butter, eggs, cheese, cream, liver, meats and rich patés. Yet the French have a lower rate of coronary heart disease than many other western countries. In the United States, 315 of every 100,000 middle-aged men die of heart attacks each year; in France the rate is 145 per 100,000. In the Gascony region, where goose and duck liver form a staple of the diet, this rate is a remarkably low 80 per 100,000. This phenomenon has recently gained international attention as the French Paradox.” — Enig, Mary and Sally Fallon. Nourishing Traditions: The Cookbook that Challenges Politically Correct Nutrition and the Diet Dictocrats. Washington, DC: NewTrends Publishing. 2001. Introduction, page 23.
Perdue, Lewis. The French Paradox and Beyond: Living Longer with Wine and the Mediterranean. Chapter 1. Page 11.
O’Neill, Molly. Can Foie Gras Aid the Heart? A French Scientist Says Yes. New York Times. 17 November 1991. Page 22.