The challenges of raising bilingual or even multilingual children is something all immigrant families are all too familiar with. Will teaching two languages cause language delays? Will it cause language confusion? Many parents have such concerns. However, there are no studies to really prove that exposure to more than one language causes any of this. Children are wired for language! So, expose them very early on. Apart from learning a language or two there are many added benefits also. Bilingual children are better at switching between tasks, they have a greater understanding of language as the abstract system and they are better at problem solving skills and creative thinking!
http://www.bbc.co.uk/news/uk-scotland-glasgow-west-19109883
http://www.cal.org/resources/digest/raising-bilingual-children.html