Boston ? The Boston Celtics signed their first-round draft pick J.R. Giddens on Tuesday. The 6-foot-5 guard, the 30th pick in the draft, averaged 16.3 points and 8.8 rebounds for New Mexico during his senior season. Giddens pleaded no contest to a misdemeanor battery charge after being stabbed at a bar fight in May 2005 while playing for Kansas. He transferred to New Mexico, where he was suspended twice in his first season.