First, let me say how awesome it is to have a centralized place for conversations about story and lore.
I thought it would be handy to post the definitive reading order for ebooks in one place, as this question keeps coming up a lot. So here you go:
The Stars of Home
Prison of Fire
Rise of the Ring
The Enemy of My Enemy
The Mage of the Teir’Dal
The Arch Mage (Parts One & Two)
Fall of Bastion
The Last Stand of the Teir’Dal
From Ash Comes Fire
I’ll keep this thread updated as new stories are released.