who sparked the 30 year's war?
2 answers
What sparked it? The change in religious services started by Luther and his allies. The Catholics, including the Pope, and his king of the area, Charles, didn't like it.
Here are some excellent sites on the Thirty Years War. Particularly, check the first three.
http://www.google.com/search?hl=en&ie=ISO-8859-1&q=Thirty+years+war&btnG=Google+Search
http://www.google.com/search?hl=en&ie=ISO-8859-1&q=Thirty+years+war&btnG=Google+Search