Bible Gateway: Read the Bible for free in dozens of translations. Also, free commentaries are available to explain passages of the Bible.
Got Questions: A very helpful site to ask questions about God, the Bible, and life from a biblical worldview.
The Gospel Coalition: Hosts many blogs and resources available from pastors, scholars, and Christians around the world.
Desiring God: Sermons, articles, and free books from the ministry of Dr. John Piper.
For the Church: Gospel-centered resources from Midwestern Seminary
Gospel in Life: Blogs, sermons, and other resources from the ministry of Tim Keller.
Christian Counseling and Educational Foundation: Articles, videos, and resources on a variety of issues from a biblical perspective.
Be Thinking: A collection of articles and media related to understanding and defending the Christian faith.
Monergism: An archive of sermons, media, articles, websites, and free books written by Puritans and authors from a reformed perspective.
Ligonier: Great articles, videos, and other resources from the ministry of R.C. Sproul.
9Marks: A ministry that helps pastors and churches think biblically about churches and leadership.
The Joshua Project: An informational site about all the people groups on earth and the Church’s progress on reaching them with the Gospel of Jesus.