I figured I would update this after my appt.
My appt was at 1pm but I got there at 12 and then had to walk many blocks back to my car to leave my backpack filled with magazines that I brought in case I had to wait there for hours. Backpacks or packages weren't allowed in the office. The officer at the door asked me for the forms and he said that they can get both FP done right away, then he asked for my passport and my marriage certificate...I was dumb enough to not realize that my name had changed. Thank God I had my license with my married name.
Since they took the FP for both (EAD and GC) I'm not sure which ones are for what. They first took some by only pressing my finger in the scanner, then picture then rolling my fingers. The lady there was complaining that I wasn't letting my hand go so she could roll it, even though I wasn't. She even pointed out this CVS cast that she has to wear because the pain that she suffers from rolling people's fingers all day.

Then I decided to roll the fingers myself and everything went better, till the very end with my little right finger, it kept giving her some kind of error and then she called this 'manager lady' and she checked it, she enlarged it and showed us some cracks, then she said 'Oh well, what can you do' and she just pressed OK. I really hope this doesn't delay my application.
The whole thing lasted for 30 min max (and 10 of those min was looking for my license that the FP lady missplaced)
can someone tell me what sets of prints are for what?