tomatoes are heavy feeders, so make sure you rotate where you plant them (new spot each year) and compost, compost, compost... and also, they love full sun and heat so make sure they get as much sun as possible. Also, the variety of tomato you plant makes a huge difference. There are hundreds to choose from. Hands down the best flavor in a tomato I have ever grown (and I know tons of people who agree about this) is the Black Krim, which is an heirloom variety, but you shouldn't have any problem finding seeds or starts. If you want to plant more than one variety, I have zillions of recommendations. I have grown dozens of varieties myself and have learned a lot from trial and error. Let me know if you'd like more info on varieties
