“Let nobody suppose that he has tasted the Holy Scriptures sufficiently unless he has ruled over the churches with the prophets for a hundred years. Therefore there is something wonderful, first, about John the Baptist; second, about Christ; third, about the apostles...“We are beggars. That is true.” - Martin Luther
"It is true that the best apologetics can be given only when the system of truth is well known. But it is also true that the system of truth is not well known except it be seen in its opposition to error."- Cornelius Van Til
"But a most pernicious error widely prevails that Scripture has only so much weight as is conceded to it by the consent of the church. As if the eternal and inviolable truth of God depended upon the decision of men!"- John Calvin
This is the best book available on Sola Scriptura. For Protestants, it will help you understand and defend sola scriptura. For Catholics, this book will help you understand exactly what Protestants mean by sola scriptura, rather than what you think it means. I highly recommend getting this book, it never leaves my desk, and serves as a valuable reference tool.
A Collection of On-line Resources For All Your Luther Needs