You can get kudos by posting great questions, or by posting insightful and helpful explanations. Also, be sure to give others kudos when you feel they deserve them!
I hope this helps!!!
Just to add on to what Brandon said, there are some projects started by the gmatclub. If you can actively participate on those projects, you will also get rewarded with kudos.
Struggling with GMAT ? Experience http://www.gmatify.com/
My Debrief : http://gmatclub.com/forum/hardwork-never-gets-unrewarded-for-ever-189267.html#p1449379
My Application Experience : http://gmatclub.com/forum/hardwork-never-gets-unrewarded-for-ever-189267-40.html#p1516961
Please click on Kudos, if you think the post is helpful