External cam to display ereaders on screen
 

I tried searching but I'm not sure my keywords came up with anything so if this has already been address I do apologize - please just point me in the right direction.

Here is what I'd like to do and I hope someone here can help me achieve it.

I'm teaching a class at a public library on eReaders (one will be the iPad). Since the class will be large I want to use a web cam (or something else) to capture what I'm doing on the different eReaders and project it onto the screen. I've tried an external web cam but VLC wouldn't work on the Macbook. I then tried the web cam on our Mac-mini using iChat. Which uses a rather small window (I'd like to have it take up the full screen) plus the wording on the eReaders is of course backwards.

Is there anything I can use on a MacBook or Mac-Mini that will allow an external source project what I'm doing on an eReader onto a screen. I need suggestions and keep in mind that we are a public library with very limited funding.

Hope this makes sense and thank you in advance for any help.

Beth