Teach their children the basics of English can be at home: suited for this colored cards (You can find the words on the Internet), songs (eg. Super Simple English), Video (eg. канал DreamEnglish на youtube). Lesson not be long, because kids can not long maintain concentration and be distracted. 20-30 minutes, then a break. Better to break training on topics (look at the tutorial). A good indicator is remembering a few words for the lesson, then complicate.