The first thing you need to know is what you are looking for. Find a picture of some wild American ginseng plants after reading this article. You can do a Google image search for ginseng plant. Notice the leaf pattern, shape, size, edges. In the fall you will typically see red berries in the middle where the flower was. Also the leaves will turn a distinct yellow. You will overlook many plants if you can not identify it by the leaves alone, though. People that just look for red berries or wait for it to turn yellow will not find as much.
You need to find out when ginseng season starts in your state. Next you need a place to go, something to dig the roots with, and something to put them in (any kind of sack or bag is fine really). Some people just like to use a flathead screwdriver to dig with. Some have "sang hoes" that they made themselves. I generally use either a weed hoe or a handheld pick hoe to dig.
Now to find some woods. If you do not have any suitable woods on your land or a friend, neighbor, or family member do not fret. You can get permits for most National Forests. You can also just simply ask someone for permission. Some will say no and some will say go ahead. Ideally, the kind of woods we are looking for would be hardwood stands of poplar, maple, walnut, hickory and beech with around 70-80% shade. North-facing and East-facing slopes are best. The ground should be moist but well-drained. Now if it happens to be a dry year the ground may be dry nearly everywhere so if the other conditions are met, it still may be a good place.
Make sure you apply some type of tick repellent or strong bug spray. Seed ticks (also known as turkey mites) are thick in the fall. Once you are in the woods, one way to tell if you are in a suitable spot is if you see some of the following wild plants: cohosh, goldenseal, trillium, jack-in-the-pulpit. You can find pictures of these by searching Google images.
Make sure you only harvest mature ginseng plants (three and four prongs) and plant the red berries back in the ground if they have not fallen off yet. When you dig a plant, first rake the leaves and debris away from it so you can see where the stalk enters the ground. Gently dig down around the stalk very carefully until you see the root. Usually you can see which way it is growing and then dig it up easier. If you are using a pick / grubbing hoe type tool though you should start digging away from the stalk and gently make your way back to the root and under it. If you happen to unearth a root that is quite small or still young, just plant it back. It should be 5 years or older before harvesting. You can count the bud scars to determine the age of the root. Bud scars look like notches along the top neck of the root.
Hopefully, you will find some ginseng roots. If so, you will need to clean and dry them. Most of the dirt should be washed off and removed. A very soft toothbrush can be good for this, but do not use a stiff one as it can rub off the outer layer of skin on the root. Then they should be spread out in a single layer to dry. A screen is great but you can lay them out on newspaper or paper towels if needed. They should then be put in a dry, warm place. 90 degrees with low humidity is close to optimal so an attic or storage building is ideal. Do not dry them in an oven or in the sunlight. Drying should take 2 to 3 weeks. When the root gets hard and breaks rather than bends it is dry. Now you are ready to sell your ginseng!