Greetings,EqualinHim,
I’m not sure what books would be best coming from a Protestant tradition. Someone mentioned the Glories of Mary by St. Alphonsus Liguori. That book is an absolute masterpiece, but you might have to take it slow. I don’t know.
True Devotion to Mary by St. Louis DeMontfort might–another exquisite masterpiece about the way to Jesus through Mary–might be another excellent resource to gradually work through.
I saw that someone recommened Tim Staples book Behold Your Mother. I love the title, but don’t have that one. I imagine that would be a good one to start with.
Right now I’m reading Dr. Carrie Gress’s book “The Marian Option: God’s Solution to a Civiiization in Crisis”. I like it a lot. You might too.
God Bless!