Go to
http://www.inkyantics.com/ and click on the box that says
Download the Instructions for
Colored Pencil Blending With Gamsol
They have a nice tutorial that should get you started! I use Mona Lisa Odorless Mineral Spirits instead of Gamsol, because I can get it locally. Others swear the Gamsol makes a huge difference. I'm not good enough at the technique for it to make a difference. LOL