Well... in my honest opinion the "Seven Year War" was two wars in one. One one hand it was the Prussian struggle with Austria to become an European major power and so the "Seven Year War" is called the Third Slesian War (There were three wars between Prussia and Austria for Slesian). Prussia was allied with Britain - Austria was allied with France and Russia (both had some minor allies - but you asked for an idiots guide so I will do it not too complicate).
So Britain and France were enemies they major battles was about the colonies. This - on the other hand - was the second part of the Seven Year War. The struggle between France and Britain about their oversea colonies.