Durga SaptaShatiThe reading of Durga SaptaShati (Devi Mahaatmyam) during Navaraatri is to be done follows:

Chapter 1 (Madhu kaitabha samhaara) is to be read for 1st day,

Chapter 2, 3 and 4 (Mahishhasura samhaara) to be read on 2nd day, 

Chapter 5 and 6 (Dhuumralochana vadha) on the 3rd day, 

Chapter 7 (Chanda Munda vadha) on 4th day, 

Chapter 8 (Rakta biija samhaara) on 5th day, 

Chapter 9 and 10 (Shumbha Nishumbha vadha) on 6th day,

Chapter 11 (Praise of Narayani) on 7th day, 

Chapter 12 (Phalastuti) on 8th day,

Chapter 13 (Blessings to Suratha and the Merchant)on 9th day

Chapter 14 (Aparadha Kshamaprarthana) on 10th dayNOTE: Do not forget the recite Siddha Kunjika Stotram ( सि�द्धकुञ्जि�कास्तोत्रम् ) after reading every chapters. 

कंुजि�कापाठमाते्रण दुर्गाा�पाठफलं लभेत् । Siddha Kunjika Stotram ( सि�द्धकुञ्जि�कास्तोत्रम् ) alone provides all the benefits of Durga SaptaShati  (ढुर्गाा�सप्तशती).There are hundreds of paths up the mountain, all leading in the same direction, so it doesnt matter which path you take. 

@Lata It does not matter as far as I can say. The best thing is reciting everyday whether it is Navratri or not. Fasting is just the way of showing respect towards the Goddess on Navratri.

As in Siddha Kunjika Stotram Lord Shiva clearly states in the first paragraph that "no argala or kilak stotra and other related matters is needed if one recites Siddha Kunjika Stotra."

Furthermore, Lord Shiva says: Siddha Kunjika Stotram is enough to yield whole benefits of Durga SaptaShati.

This does not mean one should not recite the Durga SaptaShati. If you have time please read the Durga SaptaShati during Navratri. There are very interesting and powerful stotras about Divine Mother. The Mother says whoever read Durga SaptaShati during Navratri she will be very pleased and their all desires will be fulfilled.

When you recite with the basic principles of Hinduism on cleanliness and with profound love and respect for Divine Mother