In Tamilnadu, the Navarathiri festival is celebrated usually in the month of October (the date is decided based on the lunar calendar and hence varies) dedicated to Goddesses Durga, Lakshmi and Saraswati, begins on Mahalaya Amavasya - the New moon day.  Sakthi as Goddess Durga slayed the demon Mahishasuran after a fierce battle that lasted 9 days.  The victory over evil is celebrated as Navarathiri.  The same function is celebrated as Dussera in some parts of India. 

Nava means nine & rathiri means night.  Dus is ten in Hindi.  The festival that is celebrated for 9 nights or ten days is called Navarathiri or Dussera. 

Goddess Sakthi is worhipped on the first three days, Goddess Lakshmi on the 2nd three days & Goddess Saraswathi on the last three days.  The 10th day is celebrated as Vijayadasami.  (Vijaya means victory). Prayers and pooja are offered to the Goddess on all 10 days in temples and households.  Chakkarapongal, payasam, vadai, sundal  are the traditional offerings to the Goddess during Navarathiri.  The 9th day is celebrated as "Saraswathi Pooja" or "Ayudha Pooja".  The place is cleaned and all books, tools, art, craft materials are placed in front of the Goddess for her blessing.  In factories and companies, all the machineries, tools and account books are placed in the pooja before the Goddess.  The next day on "Vijayadasami", work is commenced, new ventures started, children are admitted to school or art classes.  Students offer their respect & thanks to their teachers / gurus.  

In the temples, special pooja is offered and the Goddess (urchava murti) is decorated differently each day and taken in procession.  Music and dance events, discourses, etc are organised in temples and sabhas. 

The Dussera function is very famous in Mysore and Kolkatta.  

In Tamilnadu, another popular aspect of Navarathiri is the "GOLU".  This is the display of dolls, idols, kolams in steps (usually an odd no. of 5, 7, 9) depending on aailability of space. Mniature settings of parks, temples, scenes is very popular with the children in the family.  

Golus arranged by 
Ms.Jaishree Venkat, Chennai
Ms.Jayalakshmi Balasubramaniam, Chennai
Ms.Lakshmi Vasan, Chennai
Ms.Meena Ramamurthy, Chennai
Ms.Suchitra Subramanyam, USA
Ms.Usha Venkatramani, Chennai
Ms.Viji Vijayaraghavan, Michigan, USA