The engagement of Dawn B. Wood and John M. Shiraef is announced today. The future bride is the daughter of Janet Wood of Suwanee, Ga., and Barry Wood of Lansing, Mich. The future bridegroom is the son of Linda Shiraef. The wedding is planned for Sunday, April 7, at the Fairyland Club on Lookout Mountain. Miss Wood is a graduate of Michigan State University and the University of Georgia. She is a teacher at Lanier High School in Gwinnett County, Ga. Mr. Shiraef is a graduate of East Tennessee State University and Excelsior College. He is self-employed.