Hi!
I have added an additional widget area in the center column. But I want to display them only on particular pages. What can I do?
Any advice would be appreciated.

try using the plugin 'widget logic'

Widget Logic is fine, but Section Widget is easier for the non-progammers among us. It's fine for adding text, as in Adsense code, and putting it only in certain places.

Thank you very much. I have got a Section Widget plugin and it works just fine.