Make careful choice of the books which you read:
let the holy Scriptures ever have the preeminence.
Let Scripture be first and most in your hearts and
hands and other books be used as subservient to it.

While reading ask yourself:

1. Could I spend this time no better?

2. Are there better books that would edify me more?

3. Are the lovers of such a book as this the greatest
    lovers of the Book of God and of a holy life?

4. Does this book increase my love to the Word of God,
    kill my sin, and prepare me for the life to come?

"The words of the wise are like goads, their collected
 sayings like firmly embedded nails—given by one Shepherd.
 Be warned, my son, of anything in addition to them. Of
 making many books there is no end, and much study
 wearies the body." Ecclesiastes 12:11-12