Good morning!
I am going to assume that you have your quilt top sandwiched and pin basted.
To stipple, you need to drop your feed dogs, use a darning foot, and move your quilt sandwich in a free motion pattern of your choosing. I would recommend doodling your design on paper first (your brain will get used to the pattern because of the movement of your hand). Then try stippling on a practice quilt sandwich before starting on your quilt.
Here are a few videos and articles I found for you. I hope they help.
http://www.dummies.com/how-to/conten...nd-tricks.html
http://www.taunton.com/threads/pages/tvt035.asp
http://www.quiltmaker.com/tips/tech4/index1.html
http://www.quiltingassistant.com/stippling.html
http://www.dreamweavers-quilts.com/q...-of-stippling/