Bilingual children in the nursery class

I have been working as a teaching assistant in a primary school's nursery for the last few months. About half of the pupils use another language that they speak at home. We need to actively help these pupils to gain new language skills and not expect that they will just 'pick it up as they go along.'

Ideas for teachers of bilingual learners at nursery 
NALDIC (National Association of Language Development in the Curriculum)