If your pot is terra cotta, thoroughly soak it first by submerging it in a tub of water, laying it on its side if necessary. Leave it there long enough to become saturated with water. If this isn't done, the porous terra cotta will rapidly absorb the water you put on the soil for you plants.
Use a good quality potting soil, not soil from your garden. Strawberries like a rich soil, so you can add a little compost to the potting soil if you wish.
Fill the pot to the lowest level of pockets, and plant a plant in each pocket, carefully filling in soil around each plant. Water the soil, but be careful watering the pockets, so the soil is not washed out.
Place a 1" or 2" diameter tube of some kind in the strawberry jar, but do not position it directly over the drainage hole. Some use PVC pipe in which they have drilled many holes. Other suggestions are the cardboard center from a roll of paper, a plastic mailing tube drilled with holes and the ends removed, or as I used, a tube of wire fabric (chicken wire, hardware cloth, or welded wire) which you then fill with gravel.
Fill the strawberry jar with soil to the next level of pockets, plant a plant in each pocket, filling in soil around the plants and watering carefully. Continue in this manner until all the pockets have been planted. Then finish filling the jar with soil.
Water thoroughly. Water the surface of the soil, water around each plant in each pocket, and fill the tube with water. The water in the tube will seep into the soil to ensure that the roots of the plants have sufficient moisture. Water in this manner whenever the surface of the soil is dry to about 1/2 inch deep. The plants will need more water during hot weather, of course.
If you like, you can plant a few plants around the rim at the top of the pot, as well. You can use more strawberry plants for this, or some people plant herbs or flowers this way. It gives the planted jar a finished look.
You will want to place the strawberry jar in a spot where the plants will get plenty of direct sunlight.
"Isn't it enough to see that a garden is beautiful without having to believe that there are fairies at the bottom of it too?" - Douglas Adams