What I did was simply research, you wanna know what ARRI is, just google it and study it throughly
In other words, google is indeed your best friend
Also you should keep an eye on this forum as well, you'll find a dedicated section for almost every camera out there, and read the discussions that take place on those forums so you'd start understanding the different aspect on which people choose a camera to work with, and if there was something mentioned during that discussion that you don't understant, simply resort to your best friend google and look up!
Well, at least that's how I learned without even going to film school...