Answer:
On Etrade you would need to know/select the following:
Type in the symbol of the stock you are trying to write a put for.
Select your order type (buy open, sell open, buy close, sell close)
Select the number of contracts you want (1 contract = 100 shares in the underlying stock)
Select type ( call or PUT ) ** select put
Select expiration ( 1 month, 2 mo., 3 mo., etc.) How long do you want to hold onto the contracts before they expire?
Select Strike price (Strike price of a put is the price at which you sell the stock)
Select Price Type (market, limit, stop, stop limit, and trailing stop $)
Select term ( preselected if you select market as Good for the day)
Each of these has to be filled based on your personal decisions. There are many different strategies on how and when to buy or sell, but in the end you should make your own educated decision.