Reddit mentions of The Orthodox Veneration of the Mother of God (Orthodox Theological Texts)

Original sin is also Orthodox teaching - the Church simply doesn’t hold that there is any transmission of guilt, only concupiscence/‘desire.’ Forgiveness of original sin in baptism consists in restoring the individual to the promise from which they were separated, not the elimination of a debt.

For a closer look at the Immaculate Conception, I wholeheartedly recommend The Orthodox Veneration of the Mother of God by St. John Maximovitch. Orthodox cannot accept anything infringing on Mary’s human freedom, at the same time that they do allow for an intrinsic sanctification at the Incarnation. As a former Catholic, I know that the doctrine as promulgated doesn’t say Mary was preserved from personal sin, but it’s a corollary considered “unofficial dogma,” so to speak.

Orthodox Mariology is a huge subject, but suffice it to say that we hold the Mother of God in huge regard. The most common name by which we call her is Theotókos, which is Greek for "Birthgiver of God" (we use the Greek word because it flows better; there is no smooth, one-word translation). This word has great significance in Orthodox theology, as it is a proclamation of faith against Nestorianism, an early heresy that denied that the Blessed Virgin bore God Himself in her womb.

Here is an article on the subject of Orthodox Mariology.

Here is a book on the subject by St. John of Shanghai & San Francisco.