It’s no secret.  I think the New Testament is the greatest intermediate textbook when you are learning a language.

As soon as you are done with the grammar of a language, you are going to want something to read.  Read the New Testament.

Here is the New Testament as an audio book in Latin: http://www.bible.is/LTNNVV/Matt/1

Click on the tab NVV in the upper left-hand corner and you will find the New Testament as an audio book in hundreds of languages.

I believe there are two great strategies to fluency in any language.

#1, Get into the country of the target language.

#2, Read extensively in the target language.

This site will give you plenty to read.

http://www.bible.is/LTNNVV/Matt/1