-Surely the best product to make the best tomato sauce is...fresh tomatoes! But since they are not always delicious, especially in the winter, I love to use a product called passata di pomodoro. It's sometimes labeled as "strained tomatoes" and is available in most supermarkets and in all Italian markets. It is often sold in 24 oz (690g) glass jars. One jar will give you the exact amount of tomato needed for this recipe.
If you do have access to tasty fresh tomatoes, definitely use them. I would peel them, remove and strain the seeds (to keep the delicious juice that is around the seeds), and purée. The best methods for puréeing fresh tomatoes are either using a food mill or pulsing gently in a food processor or blender. Go slow because, if you go full speed with them, they will aerate and turn an unattractive light pink color rather than deep red.
I'm not crazy about canned tomatoes, as I find they often have a tinny flavor. But if you have a brand that you like, buy the whole peeled tomatoes, remove the seeds (if they bother you), and grind in a food mill or in a processor or blender in the same manner as above.
-The herb you use, whether it's basil, bay leaf, rosemary, or thyme, is unimportant. Just use any one of them and you're guaranteed a delicious sauce.
-This recipe makes enough sauce to dress a pound or 500g of pasta, so if you want leftover sauce after making pasta, it's best to double the recipe.