what was the information johnny found out for the rebels?

Johnny uses his connection to Dove to learn about an impending raid on Portsmouth. He tells Paul Revere about this which leads to Revere’s famous midnight ride to warn the rebels.Also, Dove accidentally reveals information to Johnny about when Colonel Smith plans to lead the assault. Johnny passes this information on to Paul Revere, who arranges for two lanterns to be hung in Christ’s Church––a signal to the rebels in Charlestown to prepare to fight. That night, the first shots of the American Revolution are fired at Lexington.

Source(s): http://www.gradesaver.com/johnny-tremain/study-guide/short-summary/