Things I Have Learned The Hard Way At the Sorbonne:
1. The History TDs (discussion sections) start after the CM (lecture). This is the exact opposite of the French Literature courses. No one will tell you this, or pity you when you become hopelessly lost.
2. The Sorbonne works on its own lines of logic. For example, the course offerings for French Literature are not in the French Literature hallway. They are in the Philosophy Hallway, because, apparently, whenever you are looking for answers you ought to turn to philosophy.
3. The bookstores near the Sorbonne will always be sold out of the books your professor strongly urges you to read/ form the basis of your literature course. Amazon.fr is a better bet. If a book is sold out both on amazon.fr and in the six bookstores you visited on Saturday, it is better to just give up. The professor will, in the next TD, absent-mindedly remark that the book she assigned has been out of print for the past year and she will send out an e-mail with a scan of the book.
4. If there is no one on your floor in the evening, while you are laborously copying out the course offerings no one thought to post online, chances are you have been locked into the Sorbonne. Head south for what I believe is a subterranean passage that leads to various lecture halls and the only unlocked door. This is the only way out, not that any of the guards will let you or your fellow bewildered students that.
5. Not all the staircases let you get off on the next floor. A staircase can take you directly from level one to level three for no easily discernible reason aside from malice.