Everyone seems to have their own things that they use, but I definitely prefer a small laptop (e.g. Mac Air) to a tablet for class.
Depending on your school and personal preferences, you may need several changes of "professional dress". There are plenty of threads on here about clothing, gender differences in clothing, etc. You can read them until you go crazy if you want. Otherwise, just take a cue from your seniors.
Someone mentioned Evernote, and I love it as well. I use it to take notes, keep track of my ToDo lists, research projects, etc. I use it all day long. You can develop your own system, but you likely will need something like that to keep yourself efficient.
Pathoma ia fantastic, very popular at my school. Definitely worth a subscription:
http://www.pathoma.com
The magic Pathoma book will basically teach you a big fraction of what you need to know in the first two years.
Kaplan QBank or another big bank of questions is basically essential for Step 1, at least for most usual methods of studying. Again, you can go through all the many threads on SDN on this topic.
I like the WhiteCoat Clipboard, and have found them very helpful. Other people think they are silly. It depends on your work mode. I saw an intern using one, and got some people in my class interested:
http://mdpocket.com/Clipboards/medical-clipboards-category
A lot of people recommend various white coat pocket accessories, some of it seems to be service dependent. I've found popping a snack bar into the pocket to be a good morning ritual, regardless.
Good luck!