Combine 4 quarts water and salt in a Dutch oven, stirring until the salt dissolves. Remove and discard giblets and neck from chicken. Rinse chicken with cold water; pat dry. Trim excess fat. Add chicken to salt mixture; cover and refrigerate 8 hours or overnight.
Preheat oven to 400°.
Remove chicken from brine; discard brine. Pat chicken dry with paper towels. Starting at neck cavity, loosen skin from breast and drumsticks by inserting fingers, gently pushing between skin and meat. Place the lemon slices under loosened skin. Sprinkle cavity with pepper; place the lemon wedges, parsley, garlic, and shallot into cavity. Lift wing tips up and over back; tuck under chicken. Place on the rack of a broiler pan. Bake at 400° for 1 hour and 10 minutes or until thermometer registers 180°. Discard skin.