Hello and welcome!
I have different issues that will be considered by the board too, and sometimes it seems hard to keep track of all of them at once. So once a month at the end of the month I would go to the records office and get copies of my medical records for that month. Then I would separate them into different categories for everything that I was being treated for. This way, not only is it easy to keep an up to date file of your medical records for yourself, but you'll be able to look through your medical records quicker and see what all the board or the VA have left out that you may feel they shouldn't have.
I don't know which MTF you'll be seen at, but the day they start your MEB packet get signed up for DTAP. This was an informative class, and you may be able to get into another class for it that is meant to get you started on your VA claim before you get out. I would also highly recommend TAP class if you plan on looking for a new job soon after you get out.
The Conditions and Ratings section on this site has a link to all the VASRD (Veteran Affairs Schedule for Rating Disabilities), which the board and the VA will use to give you a disability rating percentage. It is worth taking time to look through to find what you should be rated at. 30% is the magic number for the PEB, with this you get medically retired. Below this, and you get a severance pay.
Good luck!