The first book of the New Testament is packed full of insight about Jesus, God, the problem with humanity and God's kingdom that Jesus announced. If you want to understand what the Bible and Christianity is really about, you can't go wrong starting with the gospel of Matthew.
The Gospel Online is a YouTube channel with a large collection of talks and discussion panels that deal with many different topics in the Bible that relate directly to the good news of the kingdom of God and the name of Jesus Christ.