What books, catechisms or online sources would you recommend for (a hypothetical) someone interested in Orthodoxy who comes from a Calvanistic Protestant Christian background? This person knows a few isolated facts about Orthodox faith and practice, but gets it confused with and has trouble teasing what they know about Orthodoxy apart from the beliefs of their former faith tradition. They can only get to Orthodox services a handful of times a year because of distance, doesn't know any Orthodox Christians in their area, and is in contact with a priest who can answer the odd question, but doesn't have time to conduct a one-on-one long distance catechesis.
They are wanting a solid, even grounding on the basics of Orthodox Christian faith, belief and practice. Something reasonably concise, to-the-point and easy to understand. What materials would you point them to? Thanks