Dawn by Jim Butcher

In a world devastated by nuclear war with humanity on the edge of extinction, aliens finally make contact. They rescue those humans they can, keeping most survivors in suspended animation and begin the slow process of rehabilitating the planet.

When Lilith Iyapo is “awakened,” she finds that she has been chosen to revive her fellow humans in small groups by first preparing them to meet the utterly terrifying Oankali, then training them to survive on the wilderness that the planet has become… Read more.