Hi Jim,
Well asking in here is a good start, just bear in mind that everything you're told has an element of opinion to it and an element of fact - read every post with that in mind.
You've said you want to get into the industry, but not in what capacity. Nor whether you're doing A-levels, so what I'm saying is a bit broad.
First thing, you're not going to get an aircraft job straight off, you really need to get into a training system of some kind.
Organisations like Qinetiq (if you want to work on aircraft you'll probably have to relocate to Boscombe Down since Farnborough doesn't any more), BAe, Westlands and some of the bigger airlines such as BA still do aircraft technician apprenticeships. It'll almost certainly mean living away from home which is a big step but, hey you'll have to sooner or later. Best approach with these is simply write short, honest letters to their personnel departments listing your qualifications so far and aspirations.
If you've got A-levels the same have higher level training schemes, often leading to greater technical qualifications, which could put you on the shop-floor fixing or building aircraft, in a design office, or one of many other fascinating technical roles (as an aside, at 19 I was working at Farnborough designing - albeit under supervision - bits of Lynx helicopter).
Then there's the defered gratification approach, otherwise known as a degree. Various degrees exist in aeronautical Engineering, aircraft operations, etc. They need good A-levels and will all be 3+ years of very hard work. They also open the doors, if you care to find and go through them, to some of the most fascinating areas of the industry - flight test, aircraft design, technical instruction.
Another route, open at a wide number of levels is the military. Depending upon your age and qualifications, you can join any of the three services as an aircraft technican, engineer, armourer, etc. The jobs are interesting, the environment stimulating, the money reasonable, and the education world-class. You also have more options, if you show the ability, to change course than in many other environments, I have a friend who joined the RAF as an avionics technican apprentice at 16 and left at 38 as a Sqn.Ldr test pilot. The flip side of the services is long times away from home, getting shouted at a lot (at-least initially) and of-course the risk of being sent to war, and you if you don't think you could live with these, don't try.
Whatever route you take, good luck. The aircraft industry can be frustrating sometimes, but it equally offers opportunities for some of the most interesting things you could imagine doing. It can take some effort to find your way in, but once you have it'll be worth it.
G