I've got this one! My counselor forgot to do it, so I had to help her do it over the past week. The SSR just has some stats about the school, but then it asks for ratings of the student such as academics, sports, etc. Towards the end, the counselor can (should) upload a reccomendation letter. There is also a spot to upload an official transcript, assuming your school has it available. My counselor tried to upload it, but it said "invalid access," which probably had to do with the security on the school computers. She then had to switch to "Offline Provider" and do everything in paper, which is a PAIN.
***note the letter of reccomendation your counselor writes needs to be generic, because it goes to every school on your list