Bi-lingual babies

Being English speaking myself and with a Swedish husband living in Spain Charlie has his hands full. Up until now he is really only exposed to English at any length. You hear of it taking longer for multi-lingual children to start speaking and I do worry sometimes with the pressure of getting it right how we should best approach introducing him to all of these languages. We do want him to be tri-lingual. A friend mentioned this site and I hope it will answer many of the questions that I have http://www.bilingualbabies.org