My husband and I own a small business doing computer repairs, resumes, copy, fax, etc. and I am an ESL teacher so we want to offer some classes. I see many used textbooks online. Can I use them to teach or do I need to buy the books from the publisher. What about if I show a movie or TV show in class and use it to teach, is that ok?

Education is allowed 'fair use' of copyrighted materials in their educational purpose without getting permission from the copyright holder.

This usually means quoting a paragraph etc., maybe a chapter. Watching a TV show or movies, as long as the movie wasn't a pirate copy, would also be within guidelines of fair use.

Used textbooks would be fine. They don't lose their status just because they are used. Now if you bought one book and made copies of the whole book for the students that would cross the line.

As to the books- they are used, but they are official copies, so that's ok. In fact, colleges buy used books every semester and resell them and students buy them because they are soooooo much cheaper ( and they are highlighted :) ) . If you show a movie or tv show, you will most likely be fine because no one investigates on such a small scale. But each show or movie is different as to whether or not you can use it. Some say its fine, some want you to simply let them know, some want you to jump through hoops. But, unless you start making copies of the movies and selling them, they won't care anyway, so just use them.