Here is an interesting page of books that might help you learn to learn languages better: Language Books at Learn in Freedom.org.
I found this link through a book suggestion from Soultravelers3, who suggested the book by George Saunders:
Bilingual Children: From Birth to Teens
George Saunders (Clevedon, Avon and Philadelphia, PA: Bilingual Matters, 1988) (ISBN 1-85359-009-6). xiii and 274 pages; glossary, bibliography (which has a GREAT list of titles of similar interest), indexes. Saunders is from English-speaking monolingual ancestors, going back at least six generations on all sides of his family. He studied German in college, got to study abroad for a while, and then decided to bring up his children bilingually. The book describes his remarkable successful experiment in bringing up three children as German speakers in Australia. KMBseen_SPP
. click to see book description at Amazon. Someone else recently recommended this book to me. Unfortunately it seems to be hard to find and expensive ($47 used, $76 new). Soultravelers3 are two parents who are mostly anglophone, (father speaks some Spanish), raising their daughter to be trilingual as they travel the world. Do check out their blog.
Anyways, this Saunders book seems to be a precursor to the trilingual parenting book I like: Growing Up with Three Languages. Has anyone else read the Saunders book and recommends it enough for me to spend $50 on it?