Why does inflation help bankers and big corporations?

Aside from the two videos above, yes, definitely check out Modern Money Mechanics for yourself.

Another film(s) which does a decent job explaining this part is Money as Debt (1 & 2). Of course, as is the case with Zeitgeist, and the Bill Still films, it falls off the deep end and ends up being on net a harmful film, but if you use it for education on how the current banking system works, it can help to wrap your head around it.

For literature on the subject, see:

What Has Government Done to Our Money?,

The Case for a 100 Percent Gold Dollar, & The Case for a Genuine Gold Dollar by Murray Rothbard

The Mystery of Banking by Murray Rothbard

And

The Creature from Jekyll Island by G. Edward Griffin

The Money Matrix series by Jake Towne

(which are included with a couple of great videos here)