http://arduino.cc/en/Guide/HomePage

http://gnats.sysgo.com/gnatsweb.cgi

http://todbot.com/blog/2009/05/26/minimal-arduino-with-atmega8/

arduino without ide:

http://www.jayway.com/2011/10/08/arduino-on-ubuntu-without-ide/

http://www.joakimlinde.se/microcontrollers/arduino/avr/index.php

bootlader:

http://n0m1.com/2012/04/01/how-to-compiling-the-arduino-bootloader/