The Jewish perspective on life is that even physiological functions are tools for serving God. This is generally expressed in accordance with the teaching of our sages that "all your actions should be for the sake of Heaven," meaning that when one eats and drinks, it is to gain strength to serve God, and even when one rests, it is to replenish strength for serving God.
We say in prayer, "they (the Mitzvot) are our life," that is, they are what we live by and from which we derive life.
Regarding sleep itself, Maimonides writes, among his medicinal advice, that one should sleep eight hours each day to be healthy.
Regarding preparation for sleep, our sages established that we should say the Shema Israel Before going to sleep, along with a series of requests (printed in prayer books) so that going to sleep is peaceful and waking up is peaceful.