wbryce,
I'm myself working at Vienna International Airport for two years now.
Assuming the structure of how an Airport is working should be more or less the same worldwide i maybe can give you some useful hints.
If you wanna stay in direct contact with flight crews, ramp agents, loading supervisors or, to a lesser extend, refuelers, cleaners, catering - in that order - would help you most.
All that jobs can be both acomplished by airport personell or airline personell - so those are the right adresses for any applications. In most cases asking in some personell departments of airports would help at most for a first step.
The now following i just know for Austria - i dont know for sure about the situation within EU or anywhere else: Airports should be very secure companys - in our case: we were nearly not effected by any problems caused by 9-11 at all - AND: they should constantly be hiring. Of course it is a matter of company structure how wide your professional field will be and which career opportunities will be offered.
Stay away of loading or deicing jobs - normally you won't be in contact with flight crews, even if you want to, AND what weighs most: those jobs won't be very challenging and you might get bored just after few months (not to mention physical challenge of bad weather all the year and back pain - those are hard jobs, good money in most cases, but there's easier ways to earn it - I know what I'm talking about, did it myself for a few months)
So - that's my thoughts on that topic for now - hope something useful for you.
Chris
LOWW