Preheat oven to 400 degrees F. In a large skillet, saute sausage over medium heat until browned, about 6 minutes. Drain 1/4 cup of oil from cooked sausage. Set sausage aside to cool. Stir salsa and cheese into sausage in skillet. Place 1 tortilla on a clean work surface. Spoon 1/4 cup of the sausage mixture down the center of tortilla. Fold tortilla in half, then roll up. Secure with toothpicks. Place on a foil-covered cookie sheet. Repeat 5 times. Bake until filling is hot and tortilla is crisp and golden brown, about 18 minutes. Cut taquitos in half crosswise. Serve hot with guacamole and sour cream.