In order to plant effectively after you have prepared the area---

Get the best, healthiest looking tomato plants you can find. That means look for plants with leaves without spots or holes in them, Plants without tomatoes already growing on them, long roots not coming out of the bottom of the pack. So you want strong looking plants that do not look like they have lacked water but also not grown spindly looking.

Now plants should be about 2 to 3 feet apart depending upon what type of plants they are.

There are 2 main types::

Determinate which grow to a certain height and stop. They usually flower for a certain amount of time and stop. This type of plant grows more like a bush, The yield can be higher but if left to grow by itself without support, many tomatoes will touch the ground and rot. It can be supported with a cage or a stake and a ground cover can be used.

Indeterminate grows and continues to flower much later in the season. However it grows in a more slender way than the other type and must be supported. Cages can be used if they are very high. I prefer Stakes and I like to use Rebars which can be obtained at the local Home building Store reasonably. The Rebars last indefinitely however good strong wooden poles are fine also. Either way try to get long ones (6 feet-7 feet)

Plant tomatoes in garden:

The seedling can be planted deep in a hole or sideways in all soils. But in heavy (clay soils),especially, dig a hole and then extend it with a narrow trench. You should very carefully take off the bottom set of little leaves. Stir some compost or dried cow manure into the dirt in the hole and trench. Then sprinkle some soil over it and firm it down. Lay the plant in the trench with the root end being a little lower in the hole and now the stem sits up with the rest of the leaves intact. Be careful as you bend the stem and very gently cover with good soil so that the soil covers the plant up about 2 inches or more. Actually you can lay it down without bending it and it will pick up when watered and with sunlight. I prefer to bend it slightly without injuring the plant. The area of the stem can grow roots wherever it is touched by soil so the part in the trench will give the seedling a stronger root system to begin it's adventure.

You should always plant each one the same way-- that is, the trench is in the same direction so that when you pound the stake in you do not damage the plant. I prefer stakes because cages after 2-3 years start to get rusty and often break up, also storage is a nuisance. To me the main advantage is that the plant does not have to be tied to the cage.

After you plant it is necessary to water heavily to get the seedlings started. I like to use what I call "The Moat Method":

About 8-10 inches away from the stem, You dig down a furrow about 2 to 3 inches around the whole plant heaping up more soil around the stem and some extra soil on the outside of the ring. Now when you water especially in the beginning, fill that moat full of water, then go around and fill the others. When you are done most of the original water has sunk in around the plant. Now go back and do it again. It doesn't have to be quite that much the 2nd time but it will give the little plants a better start.

Good luck with your planting