8 to 10-inch bamboo skewers, soaked in water for 30 minutes
Thread the shrimp through the skewers at two points, through the neck and tail portion. If you compare the shape of the shrimp to the letter "C" the skewer should go through both the top and bottom section of the "C". You should have 5 shrimp per skewer. Place into a 9 by 13-inch baking dish and sprinkle with a bit of salt and pepper.
In a medium bowl, combine the roasted garlic salad dressing, lemon juice and Italian seasoning. Reserve about 3 tablespoons of the salad dressing mixture. Pour the remaining dressing over the shrimp and, using a brush, make sure all the shrimp are completely coated with the dressing. Let sit in the refrigerator for 5 minutes or up to 30 minutes.
Preheat a grill or grill pan over medium-high heat.
Brush the grill grates with a paper towel that has been soaked in canola oil. Place the shrimp skewers on the grill and cover. Cook until opaque and cooked through, about 3 minutes per side.
While the shrimp are grilling, combine the arugula and tomatoes in a large bowl. Pour the reserved dressing over the arugula, season with salt and pepper and toss to coat. Divide among 4 plates. Place 2 of the shrimp skewers on each plate. Serve with a lemon wedge on the side.