Celebration begins with Vaag Baarash, then DhanTeras, Kali Chaudash, Diwali, New Year - Nutan Varsha, Bhai Bij, Laabh Paacham and then Tulasi Vivah.   

We should understand why we celebrate:  Thanx to Google and the Contributors.

Here are some links, invest some time to understand.

VaaghBaaras:  Vaagh also refererred to Financial Debt.   On this day, one goes over the debt and clear them on their books and on Laabh Paacham, make new entries.  Also known as Guru Dwadasi for Guru Dattatray. 

DhanTeras refers to worshipping Sri Ganesh and Sri Laxmi, for removing obstacles, making way for Prosperity.  

Kaali Chaudash:   Removing Darkness of negativity praying Hanuman Chalish - Bhut-Pishach Nikat Nahi Aavai, Mahabir Jab Naan Sunaave, Naasai Rog Hare Sab Pira (Pida - Miseries), Japat Nirantar Hanumat Beera.   

Diwali (Festival of Lights):  Deep pragatya removes the Darkness.  So mantra here is OM Asato Maa SadGamay - Lead me from Unreality to Reality, Tamaso Maa JyotirGamay - Lead from Darkness to Light, from Ignorance to Knowledge - winning Asuri Demonic Tendencies by Divine Vritties.   While lighting Diya outside, may we light it within our Heart, leading to Enlightenment!  Vow What a concept!   Of course that will lead to Mritytor Maa, Amritam Gamay.   From Birth & Death cycle to Immortality.

We celebrate, Lord Ram-Sita return to Ayodhya after Victory over Asuric (Demonic) Forces.  Defeating NarkaaSur by Sri Krishna!  

What is Significance of Rangoli During Diwali Holidays:

http://www.diwalifestival.org/diwali-rangoli.html

http://www.diwalifestival.org/diwali-in-history.html

Nutan Varsh - Happy New Year: 

Lord Ram's RajyaAbhishek:  and SreeNathji started Goverdan Puja replacing Indra Puja  Indra unleashed his wrath by deluging Gokul with rain to destroy it. ShreeNathji lifting Govardhan to save Gokul.   That was followed by festival with Annakut - Food Festival.  

Bhai-Bhij:   Started with Yami (Sister) and Brother YamRaja.  Sister well wishing for her Brother.  (Brother's Day!)

Laabh Paacham - Beginning of New Accounting 

and Last one:

Tulsi Vivah:  Tulsi Vivah is the ceremonial marriage of the Tulsi plant (holy basil) to the Hindu god Shaligram ... 

 https://en.wikipedia.org/wiki/Tulsi_Vivah