This is a brilliant book if you are just starting to learn German. It uses simple sentences in a charming way, all the while introducing new vocabulary and grammar. There is also a comprehensive word list at the back.
It is about two German children who live near Cologne, Germany, with their mother and who are visited by their English cousins, Eric and Maria. However, best of all this book was written by Frau Hardy, my German teacher at Acton High School (formerly called Reynolds High School), in Acton, west London during the 1970s. She was a wonderful, dedicated teacher who made us work very hard but who we remember with great affection. R.I.P. Frau Hardy.