Islamabad, considered a cultural dead city is finally growing up and you find various cultural activities to take part in. Some of the good places to look for are:
Islamabad Cultural Forum
Pakistan Academy of Letters
Pakistan-India Forum for Peace and Democracy
Art of Living Activities
Asian Studies Group
The best would be to read the "What's On" column in the daily News, especially on Saturday and Sunday. Other than that several activities are announced through bill boards and banners through out city, so pay attention to those.