Puts are more or less the mirror image of calls. The put buyer expects the price to go down. Therefore, he pays a premium in the hope that the futures price will drop. If it does, he has two choices: (1) He can close out his long put position at a profit since it will be more valuable; or (2) he can exercise and obtain a profitable short position in the futures contract since the strike price will be higher than the prevailing futures price.
For years, the preferred method of trading options was to use a live broker with a securities firm because you would receive all the research you would need to make a judgment. But with the advances made by online brokerage companies in being able to provide you with that information, more people are trading commodity options online than ever before and they are paying a fraction of the commissions they would otherwise pay to a live broker. Since you will have more trades than you would if you were simply buying stock, you will have more money in your account.
The price at which you agree to buy the underlying security via the option is called the "strike price," and the fee you pay for buying that option contract is called the "premium." When determining the strike price, you are betting that the asset (typically a stock) will go up or down in price. The price you are paying for that bet is the premium, which is a percentage of the value of that asset.