What is the best way to grow tomatoes in the garden in the ground?

The success of a tomatoe plant is very dependent upon its root system. I even buy tall plants and plant them 3/4 in the ground after removing leaves that would be underground. This creates a very strong root system. If the end of your question was "container" then I would definitely say in the ground. Make sure you till the soil and add compost amendments for nutrition. I have also filled the hole I dig for planting with potting soil as I plant and then sprinkle a teaspoon of fertilizer beads about 6" from the base of the plant. This is good for 3 months of fertilizing. Ask around and make sure you use varieties that are known for doing well in your area.

plant in rows about 12 inches apart keep them watered and watch them grow

when watering try and water the base and not so much the leaves, it can cause mold. If you have the space and good soil I'd say at least double the 12" apart to 24". Tomatoes vine and bush and need room to grow, planting them too close together can make it difficult to gather tomatoes, and can cause longer ripening times. Plus, it just looks better than a big jumble of plants.