Nebraska head wrestling coach Mark Manning announced Tuesday that he has hired former Central Michigan assistant coach Shawn Charles to fill NU's assistant coach vacancy left by Terry Brands, who is now an assistant at Montana State-Northern.    Charles comes to the Huskers after four years at CMU where he coached the middle-weights. While with the Chippewas, Charles helped coach 10 wrestlers to All-America honors, including 1999 157-pound NCAA Champion Casey Cunningham.  As a team during Charles' tenure, CMU finished in the top-20 three times and the top-10 twice.    Charles started his coaching career at Iowa State as an assistant from 1993 to 1995.  After coaching the Cyclones, he served as an assistant at Phoenix College from 1995-96, before moving on to coach Oklahoma's freestyle club coach in 1996.    As a collegiate competitor at Arizona State, Charles became the first four-time All-American in Sun Devil history and was an NCAA finalist in both in junior and senior seasons.  Twice he was a PAC-10 champion at 126  pounds and finished his career with a 103-31-6 record (1990-93).    A member of the U.S. Freestyle team for seven years, Charles brings a wealth of international experience to the NU wrestling room.  In 2000, he vied for a spot on the Olympic Freestyle team, coming up short at 138.75 pounds.  Charles placed second at both the U.S. Open and Kiev International tournament in 1999.  He was also a member of Team USA at the Goodwill Games in 1998 that came away with gold.      "I think Shawn Charles will be a great asset to Nebraska wrestling," Manning said.  "He has a lot of experience that has helped him be a successful wrestler and a successful coach."    Manning, Charles and the rest of the Huskers open their 2001-02 season Nov. 17 in Omaha with the Nebraska-Omaha Open.