Wash out the container with a mixture of 1 cup bleach and 1/2 gallon of water. This will kill off any pathogens that might feed on the soil or plants.
Make a potting mixture of equal parts of dampened peat moss, sand and potting soil. Mix it well and fill container to within an inch of the top.
Plant the seeds in the containers according to the instructions on the packet of seeds for spacing and depth. Tamp the soil over the seeds lightly to make good soil-to-seed contact.
Water the seeds gently so that you dampen the soil well without dislodging the seeds.
Cover the top of the container with clear plastic wrap and place it in a warm spot where it will get at least eight hours of sunlight per day.
Open the plastic every day to check the seeds, water them a little and to allow fresh air in, until the seeds sprout and send up their first leaves. Remove the plastic and continue watering lightly every day.
Bring the containers outside when the last chance of frost has passed and set them where they will get the amount of sunlight that they need.
Water every couple of days during the summer and even once a day during times of high heat and no rain.