How do you teach your son different languages while he's young?

Me and my preagned wife both know spanish, english, italian and german; our home language is spanish and live in an spanish speaking region (although we might move to italy), I've heard that children can learn a lot of languages while they're young, and this is a skill we obviously want for our child, so how do we go about it? How can we teach our son since youth enough so he can communicate in these languages when he's grown up? via /r/Parenting http://ift.tt/292SxfX