Ni-Ryan
Don't drop the A-levels...The aviation business is in a boom period at the moment, but it won't last forever. By the time you get done with training and actually get a licence. Strong a-level results may be the thing that gets you hired. You just can't tell right now, so why take the risk...You might want to consider another language also, as it will help if things are tight jobwise in the UK, you might find something elsewhere in Europe
Once you're through the private pilot course:
JAR professional pilot studies (Croucher) is a great reference book. I use it quite a lot as a reference as it's easier to carry than my large manuals. It will explain in pretty simple terms how everything works on airplanes (and helicopters), and various rules and regulations.
Don't forget the A-levels......and plan on getting a degree sometime in the future. The good old days are all but gone! Your generation is going to need a solid, science based background...Nothing ever gets simpler
Good luck for the future...170