The U.S. produces more than 3.149 billion bushels of soybeans per year (as of 2013). Soybeans are used to produce animal feed, tofu, oil, margarine ,soybean flour and more. Use of the soybean dates back 5000 years or more in China. Soy provided a huge protein source for the Chinese population.
Whole soybeans can be toasted and eaten as a snack but are not very digestible. You can also roast the soybeans and grind them into flour but the same issue of digestion applies.
Soy benefits includes beneficial isoflavones (plant estrogen), a source of easily absorbed iron, and a non-meat source of protein. Sadly in the forms most common in the West, soy is not always a great nutritional option. Within soy is a trypsin inhibitor and unless it is removed the soy is very hard to digest. The best soy products to eat are tofu, soymilk (not in excess quantity) and soy sauce. Soy cheese is acceptable but tends to not taste great.