I have a page describing How to make an Arduino-compatible minimal board. The minimal setup would be:
That excludes the circuitry for uploading your code.
By the way, in the image in the question you have an LED with no resistor. That will damage both the LED and the Atmega328. You need a current-limiting resistor.
do I still need oscillators
Not if you program the fuse to use the internal oscillator.
Some have said 5v while some say 6v can someone clarify?
The datasheet says 1.8 to 5.5 V operating range with an absolute maximum rating of 6 V.
This is what the datasheet says about absolute maximum ratings:
This is a stress rating only and functional operation of the device at these
or other conditions beyond those indicated in the operational sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.
Page 2 of the datasheet says:
- Operating Voltage:
- 1.8 - 5.5V