Try this lot as a starter:
http://www.ryanair.com/site/EN/about.php
Google search should also throw up some stuff.
In any case, you're asking about corporate stuff, rather than flying stuff (which is what goes on here more).
For the corporate stuff, you're better off emailing one of the big European stockbroking houses or investment banks in London which does analysis on Ryanair and asking for a couple of recent reports on both the company and the industry. If you're able to prove your bona fides as a student, they may send you such stuff quite happily.
There are also books about Ryanair (and the wider industry); check a business school library (or even a big Waterstone's).
How long's the essay?