As more Logos users, on the forums at least, are showing an interest in understanding the seasons, lectionaries, etc. I think there is now a market for the very readable works of Paul F. Bradshaw - especially the first book listed below. They also have value for individuals interested in early church history or in Christian worship.
- Two Ways of Praying
- Daily Prayer in the Early Church
- Origins of Feasts, Fasts and Seasons
- Eucharistic Origins
- Early Christian Worship: A Basic Introduction to Ideas and Practices
I've probably recommended them before but they are still good.[:D]