Slice the bread into 1/2 inch or 3/4 inch cubes, for a total of 7-8 cups bread cubes. You will probably not need to use the whole loaf of bread.
Set the bread cubes aside. Preheat the oven to 350 degrees, with a rack placed in the middle of the oven.
Combine the garlic, oregano, basil, thyme, 1/2 teaspoon of the salt, pepper, and olive oil, and bring to a simmer over medium heat. Simmer for 5 minutes. Remove and discard the garlic.
Place the bread cubes in a large mixing bowl, and drizzle with the oil mixture. Stir and toss to combine.
Spread the bread cubes on an ungreased baking sheet. Place on the middle rack of the preheated oven and bake for 10 minutes.
Sprinkle the croutons with Parmesan (optional) and return to the oven. Bake for 5-10 minutes more, or until they are golden and starting to be crispy.
Sprinkle the croutons with the additional salt, to taste. Let the croutons cool before storing in an airtight container.
The croutons will stay fresh in the pantry for about one week.