Remove giblets and neck from turkey; reserve for other uses. Rinse turkey thoroughly with cold water; pat dry. Combine 1 teaspoon salt and 1 teaspoon pepper; sprinkle over surface and in cavity of turkey.
Cook sausage until browned; drain well. Sauté celery and onion in butter until tender. Combine sausage, sautéed vegetables, cornbread crumbs, bread cubes, mushrooms, sage, and remaining salt and pepper in a large mixing bowl; mix well. Add chicken broth, and stir until all ingredients are moistened. Stuff dressing into cavity of turkey.
Place turkey, breast side up, in a large, deep roasting pan. Lift wingtips up and over back, tucking securely under bird. Spoon remaining dressing around bird. Insert meat thermometer in breast or meaty part of thigh, making sure it does not touch bone. Bake at 325° for 2 1/2 hours, basting frequently. Cut cord or band of skin holding drumsticks to tail. Continue to cook at 325° for 2 hours or until turkey is "fall-apart" tender. Turkey is done when drumsticks are easy to move.
Remove turkey from roaster; let stand until cool to the touch. Remove dressing from cavity of turkey. Bone and coarsely chop turkey. Combine chopped meat and dressing in a large mixing bowl, stirring well. Add more broth, if necessary. Serve over Cornmeal Waffles.