I don't have the time to answer this in depth, but 1913: The Year Before the Great War by Charles Emerson seems to be exactly what you're looking for. Be careful not to adopt a teleological view of history - even though it's obvious to us that WWI 'will happen', people at the time weren't quite so convinced. The simplest proof of this is that if they knew a war was coming in August 1914, why didn't they attack during the Spring?

Here is a timeline of events starting with the assassination of Archduke Franz Ferdinand and ending with August of 1914. If you have any more questions, I'll do my best to answer them.

• June 28 - Assassination of Franz Ferdinand in Sarajevo

• July 5-6 - Potsdam meeting of the Austrian ambassador and German officials including the kaiser and Chancellor Bethmann-Hollweg; issuance of the so-called "blank check"

• July 23 - Austrian ultimatum delivered to Serbia with a 48 hour deadline attached; Serbia appeals to Russia for aid

• July 24 - Russians begin frantic maneuvering to get the Austrians to extend the time limit, to negotiate and hopefully to soften their demands; Russia also appeals to Britain to use her influence with Germany and Austria-Hungary

• July 24-25 - England calls for a conference of the great powers to work out a diplomatic solution to the crisis; Austria-Hungary, with German support, refuses

• July 25 - Serbia accepts most of the demands and the crisis looks as if it might be avoided; however, the Austrian ambassador to Serbia has instructions to accept nothing short of complete compliance and breaks off relations

• July 26 - Partial Austrian mobilization; Franz Josef approves an Austrian declaration of war on Serbia; Russian foreign minister suggests negotiations between Russia and Austria-Hungary to solve the crisis; Austria-Hungary replies that the affair concerns only herself and Serbia

• July 27 - England appeals to the German government to bring Austria-Hungary to the negotiating table; indicates its increasing impatience with Austria-Hungary's intransigence

• July 27-29 - German foreign office, in answer to warnings from its diplomats, finally begins to realize that their plan to "localize" the crisis was unrealistic and that England might well join their enemies. As a result, the Germans finally began to put meaningful pressure on Austria-Hungary to negotiate.

• July 28 - Austria officially declares war on Serbia; Russia begins planning for general mobilization

• July 29 - Austrian gunboats on the Danube shell Belgrade; England hints that she will not stand by if war comes, but does not clearly state her intentions

• July 30 - Czar Nicholas approves Russian mobilization

• July 31 - Austria issues a belated announcement that she would be willing to discuss the ultimatum to Serbia; however, German war plans now force Germany to issue an ultimatum to Russia to stop mobilizing within 12 hours; Russians did not accept the ultimatum, realizing that if they were to do so mid-way through mobilization, it would take weeks to unscramble the mess to the point where they could successfully mobilize their forces; Germans also deliver a note to France stating that if she wished to remain neutral, she would have to surrender the fortresses of Toul and Verdun; Germany undoubtedly knew that the French would refuse

• Aug. 1 - The German chancellor, Bethmann-Holweg, addresses the Reichstag calling for war and Germany declares war on Russia; France begins general mobilization

• Aug. 2 - Germans invade and occupied Luxembourg without any warning; gives Belgium a choice: either allow German armies to pass through the country or fight; Belgium appeals to the guarantors of the 1839 Treaty making her a permanent neutral and prepares to fight in self-defense

• Aug. 3 - Germany officially declares war on France and invades Belgium

• Aug. 4 - English ultimatum to Germany calling for an evacuation of Belgium; one hour before midnight, England declares war on Germany