Everything.
That's the thing. The two most common options are lots of jobs and pay-as-you go, or really big student loans.
Both have pluses and minuses.
One piece of wisdom I see regularly from the pros is to pursue a degree that isn't aviation-related.
Something you could enjoy doing for a living if aviation doesn't work out.
I think that's sound advice, but an Aviation Minor or Double-Major isn't bad either.
It's going to be really expensive, not matter how you slice it, fuel prices being what they are...
A positive attitude really seems to be critical, too. Both because you need to be able to handle your own fears and disappointments, as well as because once you hit that first job, no Captain enjoys flying with a crabby FO.
Networking and social skills also are important. You're already here doing that, do it in person too.
Sometimes "right place, right time" makes all the difference. Jobs at and around airports get you where you can hear about things going on and take advantage of anything going on around the airport that can further a career.