|MadSci Network: Engineering|
Aeronautical engineers do, really, a lot of things. First of all, they are involved into the project of airplanes, helicopters, flying machines, spacecrafts and their parts. Sometimes, they project parts for non-flying applications, such as car components and so on.
A little brief of history: in Italy, we consider the first aeronautical engineer was Eiffel, the one of the famous tower in Paris: he has never built an aircraft, but his projects about propellers (for both ships and airships) and the reticular structure of his tower (similar to the one of an airplane reticular fuselage) are world-wide known as precursors of modern design techniques.
Engineers have to know a lot of school subjects, in particular Math and Physics, with special attention to their applications. If you want to be an engineer, you must first like what you are studying: if you like planes, you will become a good aeronautical engineer without too much difficulties.
A very good site about aeronautical engineering can be found at: http://web.mit.edu/afs/athena.mit.edu/dept/aeroastro/www/core.html
Try the links in the MadSci Library for more information on Engineering.