Archduke Ferdinand was assinated on Sunday morning June 28th 1914. The reason why Austria started making plans for war is because the assassins failed in their suicide attempts and the plot origins from Serbia was revealed. An overzealous Austrian official Count Berchtold not only used this info to provoke war, he also lied to and mislead allies about his intentions until it was too late to stop the war.

The book, The First World War, by SLA Marshal covers all of the details in the first chapter. Of course there are other books with even more detail, but I would recommend this book for someone who wants solid information without excessive detail.

WWI was about territorial expansion vs retention in almost all major countries. Austria wanted territory from Serbia, France wanted Alsace/Lorraine back, England wanted to ensure its colonial security, and expansion where possible, Russia wanted to keep Serbia under its sphere of influence, Italy wanted territory carved from Austria, Germany... well the treaty signed with Russia shows how Germany was only to happy to take what it could.

Even WWII was about territorial expansion. Syria seems to be about resource control. It may lead to WWIII, but if it does its unique in reasoning. The WW part of it always relates to treaties though. Either existing prior to or made after the start of.