Alateen has been a wonderful experience for my kids ages 11, 14 and 17. I highly recommend checking it out.
I also pick up brochures from Al Anon meetings. These brochures are free and very, very helpful and easily read by a child. I leave them in the bathroom where the kids will read them and I use them as a basis for having conversations with them. These brochures have been extremely useful in our home. Their dad is an alcoholic.