[Plugin: Infinite-Scroll] Please help a dummy with CSS Selectors

I am using the theme Easel: http://wordpress.org/extend/themes/easel
and I can’t find the selectors that work…
My best try is:
#column.narrowcolumn
div.post-content
#wp-paginav
li.paginav-next
Can someone smarter than me help? I would appreciate it greatly.
I’ve been spinning my wheels for a while here.
Thank You

http://wordpress.org/extend/plugins/infinite-scroll/