In many CoderDojo clubs, including CoderDojo Dun Laoghaire, lots of kids start with Scratch. Indeed, many schools have started teaching Scratch, which was developed by MIT to help young people learn programming.
Here is the link to the MIT Scratch site, where anyone can get started immediately.
The Harvard Graduate School of Education have developed a comprehensive guide to Scratch, called “Creative Computing”, which can be downloaded via this link. It is a very extensive document, about 150 pages and is really a complete course for use by teachers, parents and young learners, which I would highly recommend.