When it comes to language, they say immersion is best. Having one adult at home speak it at all times can really help speed the learning process along, as well as make it more natural for the child to grasp. Of course, keeping it simple and conversational also helps; you aren’t going to read El Juego de Angel when you first begin reading Spanish, of course!
When it comes to learning Hindi, My First Book of Hindi Words is a perfect introduction to Hindi for non-native speakers—both children and adults. My daughter and I are both fans of the “My First Book of…” series, and we have a copy of the Spanish version at home. What’s so wonderful about these books is that they all feature practical, real-life photos rather than caricatures or illustrations, and everything is organized by a two-page layout rather than a boring dictionary format.