If using wooden skewers, soak them in lemon juice for 30 minutes before grilling. This moistens the skewers so they don't char during grilling, and it infuses the food with more flavor from the inside out.
Place rind, rosemary, 1 tablespoon oil, and 1 teaspoon garlic in a large zip-top plastic bag. Add chicken; seal bag and refrigerate 1 hour.
Combine 1 tablespoon oil, 1 teaspoon garlic, juice, salt, and pepper, stirring with a whisk.
Thread chicken and zucchini alternately onto each of 12 (12-inch) skewers. Place kebabs on grill rack coated with cooking spray, and grill 12 minutes or until chicken is done, turning once. Drizzle with juice mixture.