They are for the students to discuss with their Heads of House about their future careers after graduating from school. Sessions usually cut into a certain class hour, and are held in the professor's office. The students list their career choices, and the professors give advice on what N.E.W.T. courses to take, as well as which O.W.L.s to focus on in order to be qualified to continue.
Harry Potter's session
- "Potter, I will assist you to become an Auror if it is the last thing I do! If I have to coach you nightly, I will make sure you achieve the required results!"
- —Minerva McGonagall's ending remark on Harry Potter's Career Advice session.[src]
During Harry Potter's career advice session with Professor McGonagall, which took place during his Divination class and he was five minutes late due to forgetting, he was rudely interrupted by the then-headmistress, Dolores Umbridge, who kept making annoying scratching sounds with her note-writing, as well as remarks against Harry's ambition of being an Auror, essentially suggesting it would not be possible due to Harry's "criminal record" (which has been cleared) and poor marks in Defence Against the Dark Arts, specifically her classes (which has been deemed, by Minerva, as incompetent evaluation).
Though Professor McGonagall was at first impartial with Harry's choice of career, even suggesting he look for another career path as his current marks require a little extra effort to make it through the cut, with Umbridge's constant interruptions and insults, the meeting ended up with Professor McGonagall supporting Harry, and having a screaming argument against Umbridge.
Ultimately, Professor McGonagall was proven right; Harry did become an Auror though it was without her direct help (if you do not count the Battle).
- Harry Potter and the Order of the Phoenix (First appearance)