The faith we hold- Archbishop Paul of Finland
Entering the Orthodox Church- Metropolitan Hierotheos Vlachos
The Orthodox Church- Metropolitan Kallistos Ware
Possible more catechetical than you are thinking, but I would suggest
The Law of God by Archpriest Seraphim Slobodskoy
Orthodox Christianity Vol I-V by Metropolitan Hilarion Alfeyev
The Rainbow series by Protopresbyter Thomas Hopko
These Truths We Hold (conveniently available here on Logos).
