Never send cash. Pay by check, money order or credit card. Keep a record of your purchases with names, item numbers, prices, dates and other information that will help you in case of a mix-up or shipping error. Store leftover seeds in sealed, plastic bags and place in a cool, dry spot. Label the bags so you won't be confused the following year.
Speedy delivery is a good sign.
Some catalogs explain how plants are shipped. If the catalog doesn't, ask about shipping methods and how long it will take to deliver to your door. Let us hear from you.