At the end of last semester, I was involved in a week-long teacher training session, and facilitated a course for Japanese teachers of English. When prepping the lessons, I found a wealth of resources on the British Council teacher's site for both teachers and students.
And now, I've even found themed materials on bilingualism at the British Council Learn English site! It includes some information, a story, and several games. Although the suggested links are a bit outdated, the lesson material seems very interesting and engaging for high-level English language learners. Sometimes university students ask me if we're teaching our daughter to speak both English and Japanese, and I've found that some students express strong opinions about the issue of bilingualism. As most of these students are English majors, I would like for them to think about their opinions dealing with language issues, such as when the schools should start teaching English and how parents can support second language development at home. The more educated about bilingualism, the better decisions we can make!
British Council (resources for teachers)