Aswad bin Yazeed Radiyallahu 'Anhu says he enquired from 'Aayeshah Radiyallahu 'Anha regarding the salaah of Rasulullah Sallallahu 'Alayhi Wasallam at night. She replied:
"Rasulullah Sallallahu 'Alayhi Wasallam slept (after 'eshaa) for the first half portion of the night. He then awakened (and performed the tahajjud prayers) till the time of suhur (sehri), thereafter he performed the witr salaah. He then went to his bed. If he had a desire, he went to his wife. When he heard the adhaan, he got up. If he was in a state of janaabah (requiring ghusl) he performed ghusl. If not, he performed wudu and went for salaah".
English reference: Book 39, Hadith 251
Arabic reference: Book 40, Hadith 264