In terms of valuing option contracts, it is essentially all about determining the probabilities of future price events. The more likely something is to occur, the more expensive an option would be that profits from that event. For instance, a call value goes up as the stock (underlying) goes up. This is the key to understanding the relative value of options.
As an example, let's say a farmer is expecting to produce 1,000,000 bushels of soybeans in the next 12 months. Typically, soybean futures contracts include the quantity of 5,000 bushels. The farmer's break-even point on a bushel of soybeans is $10 per bushel meaning $10 is the minimum price needed to cover the costs of producing the soybeans. The farmer sees that a one-year futures contract for soybeans is currently priced at $15 per bushel.
However, options are not the same thing as stocks because they do not represent ownership in a company. And, although futures use contracts just like options do, options are considered lower risk due to the fact that you can withdraw (or walk away from) an options contract at any point. The price of the option (its premium) is thus a percentage of the underlying asset or security.