Skewer sausages whole, following the natural curve of the sausage, pierce the sausage about 1 ½ inches from the end and have the skewer come out about 1/12 inches from the other end on the same side, so that the sausage forms a letter “C” and the skewer cuts through the bottom and the top of the curve. The next sausage forms a backwards "C".
Place 2 to 3 sausages on each skewer depending on the size of the grill and the size of skewer. Place the shrimp in a medium size bowl, add the lemon juice from ½ a lemon, canola oil, chopped herbs, red pepper flakes and minced garlic. Stir to combine, refrigerate and let marinate for at least 30 minutes. Skewer the shrimp in the same manner as the sausage.
In another bowl place onion wedges and whole baby sweet peppers or bell peppers cut into 1 inch pieces. Toss with olive oil, balsamic vinegar and oregano. Skewer vegetables; alternating colors and peppers and onions.
On a grill over medium heat, place sausage skewers, cover and cook for 5 to 7 minutes. Turn and cook another 5 minutes or until sausages are cooked through. Cook vegetable skewers for about 4 to 5 minutes then turn and cook for 2 to 3 more minutes or until desired doneness. Grill shrimp skewers for about 3 minutes per side, brush with any remaining marinade half way through cooking.
Transfer cooked sausages, shrimp and vegetables to a platter, squeeze remaining lemon half over shrimp and vegetables. Sprinkle with salt and pepper and serve while hot with grilled Pita bread that has been brushed with garlic infused olive oil.