The blood and ash series has 6 books in it. (Blood and Ash, A Kingdom of Flesh and Fire, Crown of Gilded Bones, War of Two Queens, A Soul of Ash and Blood, and the Primal of Blood and Bone). Then the sister series, flesh and fire has 4 books in it. ( A Shadow in the Ember, A Light in the Flame, A Fire in the Flesh, and Born of Ash and Blood). The flesh and fire series is all about the gods in the blood and ash world so some prefer reading it before finishing the blood and ash series or alternating with the blood and ash series. I would suggest reading it before the War of Two Queens, either if that is reading the series before From Blood and Ash or by switching between the books. Due to huge cliffhangers, you may want to read one series at a time to save yourself. Then the final series only has one book out, the Awakening series. The first book is Fall of Ruin and Wrath. There’s not much connection to the other series yet so there’s no certain order to read that one in.