Make songs and music part of the routine. Choose songs that go along with tasks. For example, sing a song to indicate it's time to clean up or wash hands or get dressed (if you're teaching your children at home). There are children's songs for virtually just about every task you can think of, and they're not that hard to find. You can search online or go to a school supply store and check out its resources section. You'll be able to find books filled with themed songs that you can use.
Use songs to teach basic words. There's a reason there are so many themed children's songs -- they work when it comes to teaching kids. Choose some songs that teach some basic words in English, such as the days of the week or the months of the year. You can even use the childhood favorite "Old MacDonald" to teach animal words or "Five Little Ducks" to teach numbers. When there's a special occasion, choose songs that introduce vocabulary surrounding the occasion. For example, at Thanksgiving, find a song about pilgrims or cornucopias.
Teach the songs to the children. For songs that you use every day -- such as a clean-up song -- you can pretty much just sing it every day, and the kids will pick it up. However, some of the more complicated songs that you don't sing every day will require some instruction. First of all, let the children hear the song, whether it's you singing the song or them listening to a recording of it.
Talk through the words of the song. Say the words slowly, line by line, and ask the children what the words are saying or what they mean. This allows you a chance to define some of the words that the children aren't familiar with. Ask them to repeat the lines back to you as you say them.
Sing the songs repeatedly. Practice makes perfect, and children will learn the songs if you just sing them again and again. Set aside a special time to feature songs and dance, allowing them to express themselves and get some energy out. Eventually, the children will be able to sing the songs without your assistance.