How to make simple diwali design or rangoli, check out below selected videos from youtube; south Indian descendent calls it Deepavali wherelse the nothern Indian descendent calls it Diwali, there is nothing wrong with lexicon Diwali; Deepa/Di means light, Wali/avali means row or adoration.
similarly in south it is a victory celebration over slaying Demon Narakasura by Krishna/Satyabama, in north it is celeberation for day of Lord Rama returning back to Ayodhya with his consort Sita.
This diwali I made some design; Diwali Decoration Rangoli Design Youtube Collection
Diwali Rangoli
Rangoli Floor Designs

want to send some free animated e-cards check this link
To send you dipavali wishes in marathi read more;
Origin of Diwali
girl is making a rangoli in the street

for more design check this link; Funny commercial about Diwali (Deepavali)
Kolams of Southern India; Learn how to make a simple twirley kolam.