I had read a few months ago a book called the Short History of WWI by James Stokesbury. I really enjoyed it and would recommend it to you all. I was confused about one part however. After Italy left the CP and both sides were trying to sway them over I looked at what they were offering and wondered why Italy joined the Triple Entente.
Central Powers:
Nice and other parts of Savoie (Most likely)
Tunisia and probably other African colonies
Tyrol after the war
Triple Entente:
Tyrol and surrounding territories
A few colonies if I recall correctly
First off, from the first battle of the Marne up to the surrender of Russia the Entente forces were on the winning side. Italy would of course be more eager to join the winning side than the losing side.
secondly, Italy is a state with a very long coastline. With the Italian navy being dwarfed by the combined French and British navies the entire Italian coastline would be vulnerable and blockaded. Any Italian decision would be influenced with this thought in the back of their heads.
Thirdly and probably most importantly Italy had big plans for Dalmatia and bordering regions. A part of Europe that up to the first world war was either under Austro Hungarian control or influence. This arch enemy was on their border and it was obvious to the world that the empire was crumbling. It would be a fantastic chance for the Italians to give their old enemies a stab in the back to further their goals on the coasts of the Adriatic seas.