The project: pellet boiler datalogger v1.0 homepage is found here Arduino Pellet Boiler Data Logger v1 My Nerd Stuff
This is the code for the arduino only, you also need save.php to place on the (LAMP) webserver and if you wish to save data in thhe database the mysql must be setup properly to work. You can also choose to save data in a file only. This files name is data.txt.
Read more about how the ethershield i use works here: http://www.nuelectronics.com/estore/index.php?main_page=product_info&cPath=1&products_id=4
I will make a better descrribtion some day, with block diagram of how this works
dallas ds18b20 codepiece and howto connect to arduino