Begin with these two books:
At Red Sea we think that it is essential that people know the basics well. If you're new to the Christian faith these two books will provide you with a good start. If you have been a Christian for awhile, these books will remind you of what is important.
Living the Cross Centered Life: Keeping The Gospel The Main Thing by C.J. Mahaney
Christian Beliefs: twenty basics every Christian should know by Wayne Grudem, edited by Elliot Grudem
Understanding and living in light of the Gospel
The centrality and importance of the Gospel of Jesus Christ CANNOT be overstated. It is of "first importance" (1 Corinthians 15:3) and "it is the power of God" (Romans 1:16, 1 Corinthians 1:18). At Red Sea, we are committed to continually exploring the many applications of the Gospel in our lives. Below are some books that can help us do this.
A Gospel Primer for Christians by Milton Vincent
Fifty Reasons Why Jesus Came to Die by John Piper
The Gospel For Real Life by Jerry Bridges
The Cross of Christ by John Stott
Growing Mature Through the Gospel
Christ Formed In You by Brian G. Hedges
You Can Change by Tim Chester
Taking Inventory of Your Spiritual Health
don't waste your life by John Piper
Ten Questions to Diagnose Your Spiritual Health by Donald S. Whitney
Living in Christian Community
The Hospitality Commands by Alexander Strauch
The Peace Maker: A Biblical Guide to Resolving Personal Conflict (Rev Edition) by Ken Sande
Marriage and Family
When Sinners Say "I Do": Discovering the Power of the Gospel for Marriage by Dave Harvey
Shepherding a Child's Heart by Tedd Tripp
The Big Picture Story Bible by David R. Helm
Long Story Short Family Devotional by Marty Machowski
The Gosepl Story Bible by Marty Machowski
Seeking "God's Will" and Decision Making
Just Do Something by Kevin DeYoung
Prayer Praying Backwards by Bryan Chapell
Prayer and the Knowledge of God by Graeme Goldsworthy
FREE Books Online
Many of John Piper's books are available free online at desiringGod.
Monergism is an outstanding online source of articles, audio, and books. Their goal is to equip Christians in the truth by making available the finest classic articles and resources of historical orthodoxy. This is done in the hope that the church will embrace, and recover the true Biblical doctrines of the historic faith.
Monergismbooks.com - If you are wanting to purchase some solid Christian books, be sure to check out this online bookstore.