Try reading aloud this summer, if during the school year evenings have been too crowded for it. The little ones will love it, but the bigger kids will be listening in, surreptitiously. If you're dubious about family read-alouds, get a copy of The Read Aloud Handbook by Jim Trelease, who says it's never too late to begin. Help them submit their lives to something that they find to be a wonderful activity that transforms them. Such activities as baseball and reading are where the virtues are inculcated with a seriousness that is hard to match in other areas of our lives.
Baseball teaches virtues of teamwork over individual glory, and sacrifice over selfishness.
Ask any long-suffering Cubs fan about that one. And have a wonderful summer. When my daughters became teens my wife and I handed them a copy of Mary Pipher's groundbreaking book about young girls, Reviving Ophelia . He's done the research on what boys go through in our society, and he cares deeply about their well-being. This book is the result of listening to and learning about boys, and thinking about what we can do to help them become happier, more successful boys and men.