The main requirement for most herbs is a spot where they will receive at least five hours of sunshine a day. Some herbs will tolerate partial shade, like mint, parsley, and chevril. But most herbs require direct sun sunlight. Fill the rungs of the ladder with a nice enriched full humus soil that you can purchase at a garden center. Add some well rotted manure, too.
Herbs prefer a slightly alkaline soil.
The easiest way to grow herbs is from seed, but you may also start with plants bought from a garden nursery. For seeds, chose your favorite herbs, smooth out your soil in the rungs, and scatter the seeds thinly in rows. Cover them with a thin layer of soil. Keep them moist until they germinate and are well established. When they are about an inch in height, thin the seedlings according to package directions.