Bilingual books, songs and games:

I would start recomending the books I personally know. Books that you can find anywhere, in different languages. These are, for example, "The very hungry caterpillar", "Elmer the Elephant","We are going on a bear hunt", or any book from Julia Donaldson. My personal recomendation:  If you like a book and you speak two languages fluently, you don't really need that book in two languages, you can just make it. Therefore, and coming, for example, to "The very hungry caterpillar", wouldn't you be able to easily translate it to any other language? What's about the classics, as "The three little pigs", "Cinderella" or "The red riding hood"?
I sometimes use vocabulary/picture books (as for babies). They don't really need to be in the language you are working: Both, the child, and you, can just look at the picture. Just an advice for children over 3: They can  get bored. But if these happens, you can just make a game with the book, a memory game, or similar.
You can also use cultural books, so the children also get into the culture of a country, which is, after all, one of the greatest benefits of speaking more than one language.  Some of these books are:  "The Tooth Fairy Meets El Raton Perez" by Rene Colato Lainez,  "Rene Has Two Last Names / Rene tiene dos apellidos" by Rene Colato Lainez, "I Love Saturdays y domingos", by Alma Flor Ada,  is a wonderful bilingual and bicultural book. It's beautiful for any child, but particularly meaningful and special for children from multicultural families.



You can find in here some website with bilingual books. Some of them are just as a sample, and others are for sale:

http://images.google.de/imgres?imgurl=http%3A%2F%2Freadginger.com%2Fwp-content%2Fthemes%2Fginger-theme%2Fimages%2Fbooks_perros_dogs.jpg&imgrefurl=http%3A%2F%2Freadginger.com%2Fbooks%2F&h=221&w=219&tbnid=T9nc1NTeu1j9iM%3A&docid=igl-7c1lEIgoCM&ei=z9v6VqbnKMH9aeG9gvgJ&tbm=isch&iact=rc&uact=3&dur=739&page=1&start=0&ndsp=41&ved=0ahUKEwjmirbk1ObLAhXBfhoKHeGeAJ8QrQMIHjAA

http://images.google.de/imgres?imgurl=http%3A%2F%2Fcdn3.volusion.com%2Fsa2d6.yjek4%2Fv%2Fvspfiles%2Fphotos%2FHUNGRY-1.jpg%253F1458149242&imgrefurl=http%3A%2F%2Fwww.languagelizard.com%2F&h=199&w=300&tbnid=x_76u2APXloCEM%3A&docid=ji9BTRmgO-zsLM&ei=z9v6VqbnKMH9aeG9gvgJ&tbm=isch&iact=rc&uact=3&dur=780&page=1&start=0&ndsp=41&ved=0ahUKEwjmirbk1ObLAhXBfhoKHeGeAJ8QrQMIMzAH

http://www.languagelizard.com/
http://www.childrens-books-bilingual.com/
http://ielanguages.com/blog/trilingual-books-english-spanish-french/
http://www.trilingualmama.com/online-stories-for-children/
https://www.readconmigo.org/kids

Information in German/Deutsch:


http://bilingual-erziehen.de/spanisch/