Seeking Disclosure is the parent quest for seeking out the two other Elder Scrolls. It requires you to find both scrolls while the other two quests will give you finer direction in how to do so. To get the Scroll of Blood, you'll need to track down Serana's mother. This is part of this quest line. The other will require you to make it far enough in the Main Quest line to have gotten the Elder Scroll or that you go through the dungeon it is in and collect it yourself. If you need help with the dungeon, I recommend that you look in a main Skyrim guide (perhaps my own for instance?) for the quest "Elder Knowledge".
Unbound Before the Storm Bleak Falls Barrow Dragon Rising The Way of the Voice The Horn of Jurgen Windcaller A Blade in the Dark Diplomatic Immunity A Cornered Rat Alduin's Wall The Throat of the World Elder Knowledge Alduin's Bane Season Unending Fallen The World Eater's Eyrie Sovngarde Dragonslayer
Loss of Innocence With Friends Like These Destroy the Dark Brotherhood! Sanctuary Mourning Never Comes Whispers in the Dark Silence Has Been Broken Bound Until Death Breaching Security The Cure for Madness Recipe for Disaster To Kill an Emperor Death Incarnate Hail Sithis!