What is Zoroastrianism and the Avesta?

I only know it's a very ancient religion.

Do some people still follow this religion today?
Is this the oldest religion known?

Hinduism has no recorded beginning, therefore it is the oldest.

I don't think Zoroastrians are in any great numbers today

Its still alive and well in Iran i believe

Its a religion where you try to do good rather than bad, keep to Aisha (good) rather than Dru (lie)

some sects of Islam believe it was one of the initial "imperfect" revelations of the word of God through Avesta Zarathustra (Zoroaster)

(hope i ha vent done it a disservice by my description!)

dating varies as to when the religion emerged, it possibly emerged at parallel to the Mosaic religion.

he res a link to some info

http://en.wikipedia.org/wiki/Zoroaster

Principal Zoroastrian belief - Ahura Mazda is the beginning and the end, the creator of everything which can and cannot be seen, the Eternal, the Pure and the only Truth.
Kind of sounds like what the Christians are claiming about their god Jesus yet this is just a few dozen centuries older

Probably the oldest monotheist religion. There is much debate as to how old it is and ranges from 6000 BCE - 650 BCE. Most likely sometime between 1500 BCE and 1000 BCE.

It was the state religion of the Persian empire.
There is a Zoroastrianism influence in Judaism. Abraham was born around 1800 BCE (year 1948 of creation by the Jewish calender).
Even Prue-Hinduism has an influence from Zoroastrianism.