Growing Tomatoes

There are two types of growth habits for tomatoes: determinate and indeterminate. Determinate tomatoes are more compact and bush-like (usually under 4 feet). They are sooner to harvest and have a shorter harvest window. Indeterminate tomatoes are vining and need more support and pruning. They have a longer lifespan and a longer harvest window.
Hybrid tomatoes are noted with an F1 after their name. Hybrid plants are usually very vigorous growers and have great yields of fruit. They are created intentionally by breeding two varieties together (which is different from GMO), and the seeds from the tomatoes that they produce would not grow the same tomato as your plant.
Heirloom tomatoes are always open pollinated (which means they are naturally pollinated by wind, insects, birds etc), and they will produce the same plant as the parent). Heirloom varieties are often passed down from generation to generation, and can be less disease resistant than other varieties, but will not have as high a yield as a hybrid plant.
Tomatoes can safely be planted outside when nighttime temperatures are consistently over 50 degrees. Choose a nice warm spot in your garden for your tomatoes to grow. You want at least 6-8 hours of sunlight a day if possible. When planting tomatoes you want to make sure you plant them about 18-24 inches apart and quite deeply. You can remove lower leaves if they would otherwise be buried by the soil. It is best to decide on a method of support or staking the plant, and put that into place while the plant is still young and small. A tall tomato cage is a great choice, but you have a lot of options of how to accomplish this. Tomatoes like consistent watering, and it's best to water right at the soil level and keep moisture off of the leaves as much as possible.
Tomatoes are heavy feeders and would love to have some additional feedings of fertilizer. I like to put a small amount of organic fertilizer into the planting hole. You should then also side-dress the plants (sprinkle the fertilizer around the base of the plant and rake in with your fingers, then water) 3-4 weeks after planting then again 3-4 weeks after that.