Many times the best tool is the simplest. When you first get to the hospital, have a friend bring you a notebook - the kind with the plastic zip envelope inside - and a pen. You are about to be bombarded by a million details, dozens of people, instructions for medication, follow up appointments, etc. You will meet police, detectives, nurses, counselors, physicians, prosecutors, victim advocates, etc. You will want to stay in touch with these people. Date and time everything. Get names because down the road you are going to thank these people.
Write down what the victim says and your own feelings.
In addition, this information can be a lifesaver down the road if/when things go wrong.
My mother and husband both taught me the value of a good notebook. They write down everything. My mother actually knows the old fashioned art of shorthand. During the trial of my son's attacker she sat in court, outfitted with a listening device, and simply took everything down. Later, when we got the official transcripts I was impressed at how accurate my mother's notes were.
As your saga continues keep the notebooks going.
Fill them up and keep them forever. If you have to complete legal forms, such as a complaint you have a record that can stand up in court.