also, dont just speak about it from an islamic point of view...speak about it from logical point of veiw as well. so yh appeal to their common sense becuase they dont have that level of iman/understanding that we do
you shouldn't raise 'misconceptions' you should let them raise their own misconception and then take it from there.. in other words don't go in and say, ok let's discuss the misconception of women's oppression in Islam, as it is presumptive on your part that all who come in think women are oppressed in islam. Also you want to make it more interactive..
You should also asked them the terms in relation to what? other religions, secularism, etc and take it from there.. you should be very relaxed about this, it is a piece of cake.. I'd be unrelaxed if I felt I had something to hide, but this is your opportunity to offer da3wah by invitation on a large scale, so you've got to go get em..
get a nice power slide and knead and mold that audience.. God I love moments like these...throw in some art too people love that, it makes it more interesting and relaxed setting.. like Islamic fractals or the water clock that Harun Ar'rachid gave to Charlemagne that sent his court men afright from its sophistication ...