Sola scriptura (by scripture alone) is the doctrine that the Bible is the only infallible or inerrant authority for Christian faith, and that it contains all knowledge necessary for salvation and holiness.
There are some, however, that preach solo scriptura, the belief that the only thing a Christian should read and study is the Bible itself.
What does the Bible have to say on the topic? While we are commanded to diligently teach our children the Word of God and to discuss it in every aspect of our lives (home, work, travel etc.), Paul (that great proto-missionary) was well versed in pagan literature and even quoted from it when evangelizing said pagans. In Acts 17, the famous Mars Hill sermon, Paul quotes Epimenides of Cete (“in him we live and move and have our being”) and Aratus (“For we are indeed his offspring”) applying both to our Heavenly Father. Paul, through his study of culture as well as scripture, was able to reason with unbelievers, being used effectively by the Holy Spirit.
Fear of the Lord is in deed the beginning of all knowledge, and He has commanded that we be transformed by the constant renewing of our minds. Do not settle for a weak mind. By all means, read secular periodicals and familiarize yourself with pagan arguments. Prayerfully and humbly further your temporal knowledge in order that you may more effectively speak the Gospel, the Good News of Jesus Christ, into an unbeliever’s life.