What camera to use for classroom/lecture recording?
have a look at these (I don't know your price range so I leave options in the link):

http://www.logitech.com/en-us/webcam-communications/webcams

Update:

For more professional solutions:

http://www.crestron.com/resources/product_and_programming_resources/catalogs_and_brochures/online_catalog/default.asp?jump=1&amp;model=CAPTURELIVEHD

combined with:

http://www.crestron.com/resources/product_and_programming_resources/catalogs_and_brochures/online_catalog/default.asp?cat=1058&amp;subcat=1506&amp;id=2220