Dragonsdawn by Anne McCaffrey

Readers who for two decades have been following the fortunes of the dragonriders and other inhabitants of the planet Pern will welcome the latest volume, chronicling the early years. It stands very much on its own, however; knowing about the later history of the planet only adds enjoyment. After 15 years of cold sleep, 6000 colonists land on Pern, seeking a simpler existence, escaping the aftermath of interstellar war and an overly technical society. The colony prospers until the consuming Threada force that destroys all life it comes in contact withmakes its first appearance.