In a large pot, bring 4 quarts of water to a boil. Add rice vermicelli and boil for 5 minutes. Add oil to pot and mix for 30 seconds. Drain and immerse vermicelli into cold water. After vermicelli has cooled, drain and set aside. Mix together green onion, mint, cilantro and garlic. Assemble all the ingredients. One at a time, immerse a rice sheet in a bowl of warm water to soften the sheet for handling. Carefully remove it and spread flat on a dry towel. Working quickly on one spring roll at a time, place a small amount of herb mix onto the softened rice sheet. Place a small quantity of desired assortment of shrimp, crabmeat, rice noodles and remaining vegetables on top. Too much filling may make it difficult to roll. Tuck in the sides of the rice sheet and roll up tight, like a burrito. Repeat steps 2 and 3 until all filling is used. Cover with plastic wrap and chill until ready to serve or serve immediately with your favorite dipping sauce, such as peanut sauce or soy sauce.