My Tomato 101 suggestions are simple. 

For Sandwiches:  I prefer a large, meaty beef steak for my sandwiches when they are in season.  However, a good substitute for beef steak tomatoes are vine-ripened tomatoes, which are available all year round.

For Salads:  I love any heirloom tomatoes during the height of the summer season for my salads.  When not available, I look for the reddish-brown Kumato tomato, which I tend to find all year round.  When I cannot find Kumato or heirloom tomatoes, I look for smaller tomatoes for my salads, which tend to be sweeter.  For example, the Campari, Sweet 100, and Greenhouse Grown small tomatoes make great salads. 

For Sauces:  For tomato based sauce, I like the plum tomatoes.  When in season, I prefer the ones from New Jersey.  When not in season, I make my sauces with the famous San Marzano tomatoes, imported from Italy.  The best quality San Marzano tomatoes in cans are whole.

San Marzano tomatoes:  My father grew the sweetest cherry tomatoes in his garden in Sicily, and my parents harvested those tomatoes to make the most undeniably delicious tomato sauce that was carefully bottled, stored and used throughout the rest of the year.  I don’t have my father’s garden, nor his green thumb, so I typically make my sauce from canned San Marzano tomatoes imported from Italy. 

The San Marzano tomatoes are meaty and sweet and contain very few seeds.  I add them straight from the can to the skillet to make delicious tomato-based sauces.  I do have my favorite brands and encourage you to taste and choose your favorite.  If for any reason you cannot find your favorite or the product is not as sweet as you would like it, you can add a pinch or sugar or a small drizzle of honey while cooking the sauce to help it along.

Cherry Tomatoes: These glossy red and sometimes yellow tomatoes are smaller than most tomatoes and are often enjoyed in salads.  My father grew loads of cherry tomatoes, and I love to use them in salads and made into pasta sauces.  One quick cut down the middle results in a burst of flavor to many dishes.