I recommend you to look for translations of books that you like to read in English. For example, I use the Russian version of Harry Potter 1 to learn Russian, as I am well familiar with the German version. Choose only texts / books that you enjoy - your brain forgets all boring (= irrelevant) information. As for the international literature, search the respective article on the English Wikipedia website. Then, select "German" in the column on the left side to find out what the equivalent title of the German book is.