It’s possible to do the task with history log, but you have to ask your instructor or your friend to turn on History log before they do an exercise. And it’s be better if they save the log file in metadata, so you need not to carry the text file along with your image file.

But for your case using photoshop action might be more suitable. You can ask your instructor to record new action before doing the exercise, so all you have to do is to save the original file with the action file. When you need to review the process you just open the original file and run the action anytime you want. You can also review the setting for each process by using action palette. The primary advantage use action is you can get visual of the process, instead of only plain text with history log.

You may also want set the Action Playback Option (in action palette menu) to step-by-step or even pause for some second between each process to see effect for each process. To slow down the action will allow you to manually stop the action to review effect and resume to continue. And also it’s very helpful to take first snap-shot of original image just after you open file to easily go back to rewind the process.

Please note that photoshop action will not recognize undo precess. If your instructor press undo while record action, all successful process will record to the action. This may cause duplicate or unwanted processes. But you can remove it manually anyways.

See also Using Photoshop action or browse our photoshop action main page for more resources here.

Lastly I already update this post with additional information about history log and some history option, please check it out

I hope this will be useful, If you still have any question please feel free to post you question here.

Possible?