Heat oven to 350°F. Spray cookie sheet with cooking spray. In 10-inch nonstick skillet, cook beef and onion over medium-high heat, stirring frequently, until beef is thoroughly cooked; drain.
Stir in taco seasoning mix and water. Reduce heat to medium; cook about 5 minutes, stirring frequently, until water has evaporated. Remove from heat; stir in beans.
If using crescent rolls: Unroll dough; separate dough into 8 rectangle. Firmly press perforations to seal. If using dough sheets: Unroll dough; cut into 8 rectangles.
Spoon about 2 tablespoons beef mixture and 1 tablespoon of the salsa onto each rectangle; spread to within 1/2 inch of one short side. Starting with other short side, roll up each rectangle; pinch edges to seal. Place seam side down on cookie sheet.
Bake 18 to 23 minutes or until golden brown. Top each burrito with cheese; bake 2 to 3 minutes longer or until cheese is melted. Serve garnished with sour cream and olives.