For the CFII, the FSDO wanted to see my test score sheet, a Form 8 that says I was an instructor in something That was pretty easy.
For the type rating, they wanted a Form 8 and an ARMS printout showing PIC time. We don't log PIC time so I have to convince him that Primary time was the 'same'.
Every FSDO is different though. The process isn't spelled out anywhere and they don't do this often. Just print off every document you can find with your name on it saying you are a pilot. I had FEFs, 1522s, the forms you get when you graduate IQT, ARMS printouts, etc. The more, the better.