Scholar theme widgets query

Hi there

I'm using wpmu 2.9.2 and buddypress 1.2.2.1 and using scholar theme
I had this question since long time and I think it's the time to let it out

while configuring widgets I came across 3 of them and I donno how do they work

left-sidebar
3colleft-sidebar
3colright-sidebar

I tried using left-sidebar instead the default-sidebar but I saw nothing so I prefered sticking to the default one

I like to know how 3colleft and 3colright sidebars work and how to switch them on

I like to show extra column on homepage and posts if that possible for adding some ads contents and that what make me look around for an answer

I read the PDF file attached to the theme, I watched the illustration movie for scholar theme but I end up with No answers for my question

I came across templates things but I have No idea about them and to change them or activate anyone of them

I'm building 2 websites now and both own you everything, I was lost before being a premium member in here

Thanks for help guys