The commemoration of the Dormition of the Theotokos and the preparation for the Feast begin on August 1 with a period of fasting (August 1-14). A strict fast is followed on most of the days (no meat, dairy, oil, or wine), with the exceptions of fish on the Feast of the Transfiguration (August 6) and the day of the Dormition. Oil and Wine are allowed on Saturdays and Sundays.
On the weekdays before the Feast, Paraklesis services are held in most parishes. These consist of the Great Paraklesis and the Small Paraklesis, both services of supplication and prayer for the intercessions of the Theotokos.
With the Dormition Fast, our Church provides us with yet another opportunity to repent of and let go of the things that separate us from God and from each other, to put God first and our own desires last, helping us to become like the Theotokos, the obedient servant of God, who heard His word. As Fr. Thomas Hopko said, the Most Holy Mother of God heard the word of God and kept it so well, that she of all women in history was chosen not only to hear His Word but give birth to Him. So while we fast in contemplation of her life, we are preparing ourselves to live a life in imitation of her. That is the purpose of the Dormition Fast.
The History of the Service of the Small Paraclesis to the Most Holy Theotokos, here
The History of the Service of the Great Paraklesis to the Most Holy Theotokos, here
The Service of the Small Paraclesis, here
The Service of the Great Paraclesis, here