I understand France, Russia, Germany and especially Austria-Hungary but how were Britain responsible for Germany going into Belgium.
Definitely check out this post of mine from the past for a 'big picture', no trees just the whole forest, view of things:
Ultimately the extent of Britain's involvement is that they existed and had a massive navy, one which Germany wanted to negate. At first this meant outproducing them in short range, heavily armored dreadnought class ships to contest the North Sea and later by having such a massive fleet that the British would be too scared to engage. The higher level purpose of this buildup was to attempt to show Britain that war would be too costly and thus force an alliance. It obviously did not work.
Of all powers though I find Britain having the least convincing case of 'guilt', especially in the July Crisis. Britain had a defensive alliance with Belgium since 1839, the Treaty of London. It was well established by this point -- Belgium was the ally of Britain and she would not be taken over by a foreign power full stop. Germany understood this fully and invaded regardless, not because of something Britain "did" but because it was a more efficient route to invade the French. Ultimately Belgium was considered little more than a speed bump for the Germans, not a massive point of contention.
^ These answers should be pertinent
Concerning Germany, Austria-Hungary and Russia, there is little debate; the former two were largely responsible for the outbreak of war, while Russia and Austria's jockeying in the Balkans had set-up the backdrop for July 1914 in the first place.
Britain had little role to play in the outbreak of war, and bears no responsibility for what happened. Grey supported peace offers during the crisis, and did not declare support for the Franco-Russian Entente, so as not to embolden them, while it was also clear that if the continental Balance of Power were threatened, Britain would intervene. The German decision to invade Belgium ignored this, despite the fact that had the Germans NOT expanded the war west, it is unlikely that Britain, or even France, would have entered the conflict, which would have remained confined to eastern Europe.
As or France, their situation was the same. The rhetoric of Viviani and Poincare in St. Petersburg, often referred to as a French 'blank check' was classic alliance posturing, and when they returned to Paris Viviani especially made it clear that the Russians should not escalate the crisis, and was stunned by Russian mobilization.
The Russians and the French were aware of the 'Blank Check', and the French fully expected the Germans to concentrate against them first, hence why they began to prepare their armies, but they held them 10 km back from their starting positions, to avoid being to provocative. Beyond this, the only reason the French found themselves at war in 1914 was that Germany had invaded them, with Alsace-Lorraine having little to nothing to do with the events taking place.