Find documentation and examples in the wiki.
UPDATE: March 5th, 2014 - I have too many things going on in my life right now to really give SlickGrid support and development the time and attention it deserves. I am not stopping it, but I will most likely be unresponsive for some time. Sorry.
UPDATE: This repo hasn't been updated in a while. https://github.com/6pac/SlickGrid/wiki seems to be the most active fork at the moment.