Second that. If you must study anything before you get stuff from the airline you should spend some time brushing up on IFR regulations (a lot of guys have trouble with this stuff) and maybe some swept wing aerodynamics and general jet aircraft systems (if you've never been exposed them before it can be a lot of new stuff to digest). The key is be general. The airline will teach you the specifics they want you to know the way they want you to know them.