Everyone can learn a lot about languages from Kato Lomb, I think she is the greatest self taught polyglot in modern time.  She spoke many languages fluently and was able to work as a translator, even as a simultaneous interpreter. Her success was attributed to great amount of comprehensible input through reading . This is the link for her book, on how to learn languages , voila:

http://www.tesl-ej.org/books/lomb-2nd-Ed.pdf