My friend David Marsh just published his book Doubt Not, But Be Believing: Supporting Loved Ones through Their Trials of Faith.
Even though doubts may come, we can stay strong. This book will help you understand how to support someone who is dealing with doubts about the Church. David has decades of experience in teaching, writing, and helping people understand the context and framework for understanding the truths of the Gospel. In this book, he helps you examine common sources of doubt, shows you how to find answers to tough questions, and teaches you to address these struggles as the Savior did.
Learn more at doubtnot.net.
For simple, official explanations of gospel doctrines, practices, and historical events, see Gospel Topics (topics.lds.org).