A word of advice. DO IT SOON as you possibly can, don't wait!! When I was hurt, my Pl WO. got the ball rolling almost immediately with the DVA and SISIP. He brought all the forms to me and I filled all the forms while still in the hospital. Glad he did because after I was released there was no waiting period. I had my VA pension while still serving (another 24 months) and within a few weeks after my release date i received my first SISIP payment.
Doing it quickly as possible also allows you to be more accurate on the CF-98 and other forms because the incident is still fresh in your mind. Details are everything, put as much detail as you possibly can and remember, including, times, dates, places, i.e location were injury occured in detail, witnesses and witness statements., Clarity, clarity, clarity.
Keep a copy of "EVEYTHING" and start your own file, Including witness statements. A photo copier is your best friend.