I didn't expect to ever teach. Given that my undergrad major was one that had good job prospects (in other words I wasn't an English or Fine Arts major), I had no reason to expect to teach. The only reason I became a TA in grad school was to offset the cost of tuition (I was an international student; tuition for international students shocked me more than the toddler-sized bed in my dorm room). Had I known that immediately following graduate school, I would end up teaching, I would have paid a lot more attention to all things pedagogical.
That said, there are just some things I'm guessing no one ever considers mentioning in any program to anyone. Here is my list of "things they don't teach you before you become a professor." Feel free to add your own to this list.
10. You will be surprised how rage filled you will become if the professor before you leaves the white/chalkboard completely filled with his/her notes.
9. Same goes for if the professor keeps his/her class late and causes your own to start late.
8. The day you lose your voice or have a guest speaker is the day the grounds crew will be mowing and/or leaf blowing right outside your window, but only for the duration of your class. As soon as you excuse class to leave early, they will move on to find someone else who is attempting to do student presentations.
7. I've included this before, but it must be said again: Adding the begging, seemingly sincere student to an already-full class because he/she couldn't get his/her shit together to register ahead of time will become your single most regrettable moment of the year.
6. If there is an important key to be used for any important storage cabinet or room, the least logical person in the whole building is going to be the one in charge of it. In our building, that person is the professor emeritus who teaches special classes only on weekends. There will be no other copies of this key.
5. No tech equipment ever works like it should. You just have to learn which cord not to use and which remote never has batteries and which document camera will always flop down to point directly at your crotch when you turn it on.
4. If there is a clock in the room, it will not have the right time and will be positioned in such a way that only someone with an 80-foot ladder will be able to reach it.
3. If you plan to use PowerPoint or some other such program in class using your own equipment, your email will pop up with something embarrassing. Even if you have never watched porn in your life, that is the moment your equipment will choose to reveal to the class that you are a sick, sad pervert.
2. The least competent person in the department is going to be teamed up with you to co-teach or work on a committee together.
1. Anything you attempt to draw on the board (Anything!) is going to look like a penis.