In a small bowl, combine together rice vinegar, sugar, and salt. Stir well and set aside for the sugar and salt to dissolve while the you cook the rice.Place 2 cups of dry rice into a fine mesh strainer. Rinse rice under running water 30-60 seconds. Strain thoroughly and place cleaned rice into your rice maker or into a medium saucepan. Fill with a full two cups of water and if using a rice maker, turn on to cook.If cooking on the stove, place saucepan over medium-hight heat. Bring to a boil, reduce heat to low, and cover the pot with a tight fitting lid. Continue to cook rice until all of the water is absorbed. Turn the heat off and let rice steam in the saucepan with the lid on for an additional 10-15 minutes.Transfer the rice to a shallow dish and gently stir in vinegar mixture. Cover and let sit for a few minutes to absorb the seasoning.Cover a bamboo sushi rolling mat with plastic wrap. If you don't have a sushi mat you can use a kitchen towel lined with plastic wrap.Place a sheet of nori, rough side up, on the mat. I like to use a full sheet, but you can also cut in half and use a half sheet for a smaller roll. Just be sure not to place too many fillings on a half sheet roll.For a full sheet, spread a thin layer of the seasoned rice across the nori. If you dampen your fingers with water, it will help the rice not to stick. Below I will show you 3 different ways to roll.#1. For Regular Sushi: Begin placing a thin line of each vegetable in a pile horizontally along the lower third of the wrap (see photo below.)#2. For Inside Out Sushi: Sprinkle some sesame seeds over the rice. Lightly wet your hands with water and gently pat the rice. This will help the rice not stick to the mat when rolling. Flip the nori upside down, so that the rice side is now touching the mat and the seaweed side is up. Place a line of each veggie into a pile along the bottom third of the nori (see photo below.)Begin to roll the sushi away from you using the bamboo mat. Be sure to tuck in the vegetables as you go and roll the sushi into a tight log. Place the sushi roll on a cutting board and lay the mat over the top of the roll. Use your hands to firmly even out the roll again, reinforcing the tight roll.With a dampened sharp knife, cut the long roll in half. Line the two halves up and cut in half again. You should have 4 equal pieces. Now, cut each half in half and you should have a total of 8 pieces.#3. For Avocado Dragon Roll: Roll an inside out sushi roll and set aside. Take half of a large avocado and carefully peel the skin off. Place the avocado flat side down on the cutting board. Using a sharp knife, cut the avocado horizontally into thin slices. Gently fan out the avocado to the length of the sushi roll. Carefully lift the fan of avocado and lay it on top of the prepared roll (see photo below.)Place a piece of plastic wrap on top and with your mat or a kitchen towel, shape the avocado around the roll. (If using a mat, it may leave slight indentations)Use a sharp knife and cut the roll into 8 equal pieces. Remove the plastic wrap and serve immediately.Serve sushi rolls with tamari or soy sauce, wasabi, and pickled ginger. Makes about 6 rolls, depending on how much rice you use in each roll.