Chandi Path -01
The Devi Mahatmyam is a collection of 700 Slokas on Sri Durga from Markandeya Purana
You can read Durga Saptashati Sanskrit+English
Navaratri is celebrated four times a year. They are Ashada Navaratri, the Sharada Navaratri, the Maha Navaratri and the Vasantha Navaratri. Of these, the Sharada Navaratri of the month of Puratashi and the Vasantha Navaratri of the Vasantha kala are very important.
It is stated that Durga sat on the tip of a needle for nine days, doing a severe penance to destroy the evil Asura Mahisha. On the first three days, she meditated as Herself, the next three days as Mahalakshmi and the last three days as Sarasvati. This signifies progression from tamsik, to rajasik to satvik and eventually obtaining liberation. The tenth day during Sharada Navaratri is called vijayadashami to signify the victory on the day of dashami. It is, however, a long tradition that one reads the devi-bhagavatam or the devi mahatmyam (Durga saptashati, 700 verses on Durga) during this period. Devi bhagavatam notes that Rama meditated and fasted for nine days after Sita was kidnapped by Ravana.