AVR Chips on the arduino uno come loaded with a bootloader to run the usb communication & arduino stdlib. This is how to go from a blank chip to a flashed chip.

Pin connections:

Atmega328P DIP Pinout

16MHz Crystal across PB6/PB7
connect 22pF bipolar caps from the crystal to ground:

                             GND
PB6 ----------|-------[22pF]--|
          [Crystal]           |
PB7 ----------|-------[22pF]--|

Pin R10k pullup to +5V
AVCC connected to +5V
also might be useful to have pwr indicator LED

• Start by Loading File → Examples → 11.ArduinoISP → ArduinoISP
• Connect seperate Arduino UNO board (hereafter called the programmer) to pc via usb.
• Upload the ISP sketch to the programmer.
• Install the MiniCore library and install the MiniCore boards
• Wire the following connections from the programmer:

10 -> MOSI  (17)
11 -> MISO  (18)
12 -> SCK   (19)
13 -> RESET ( 1)

Arduino as ISP wiring diagram

• Select the programmer method as Tools → Programmer → Arduino as ISP
• Select the Atmega328 in Tools → Board and make sure the variant based on the chip you have.
• Set the clock to 16MHz external (or whatever you are using).
• Burn the bootloader with Tools → Burn Bootloader

From the ISP dongle, make the connections to the chip

Then upload the code with Sketch → Upload using Programmer.