A step-by step approach to starting with an tinyAVR microcontroller.

Using a bare-metal approach
• Bare SOIC-20 chip on a protoboard PCB
• Using command-line avr-gcc compiler
• Little demo application to blink a LED
• Readable make-file to perform all development steps
• Using avrdude and a USB-serialport to download firmware into the target

See this link for more details