I don't really understand how to hack it. What programs do I need? Can I make Custom Jobs? Do i have to have a memory card or will it work on a PS3?
The basic programs are FFTPatcher for editing items, abilities, jobs, etc, FFTacText for changing text, Shishi Sprite Editor for spriting, CDMage for importing files (these files can be found on the main site (http://www.ffhacktics.com)) , and ePSXe emulator, with all the plug-ins. If you're going to do spriting, it wouldn't hurt to have a program such as Adobe Photoshop or Corel Paintshop Pro.
Yes, you can make custom jobs, but you have to get rid of current jobs to do so, unless you want to expand your ISO.
As far as the PS3 thing goes, unless you have Linux, no. And even then, it will lag severely and it won't be any fun. I recommend downloading the ISO from the internet somehwere (I can't tell you where, because it's illegal to download unless you have a hard copy of FFT), and playing it in ePSXe emulator.