This link will show basic setup instructions.
Learn how to get started with off-camera flash using nothing more than your Nikon dSLR and an external speedlight.
www.cnet.com
I understand the frustration. Speedlight does Work ! I have the WS560 which is similar to YN560 and a Nikon D7000.
Fresh Batteries is very important. Replace AA batteries after 2 hours of usage or 50 flashes or until it stops working properly.
If a blinking blue led is lit reduce the Speedlight flash power until it changes to a red LED.
On the menu item e3 or bracketing / Flash navigate to commander mode.
Note the flash shutter speed 1/60th sec and the flash sync speed 1/250sec.
My camera exposure settings are 1/160s f8 iso100.
Press pop up flash button on the left hand side near the top and hold as you view the menu on top of the camera. Mine is set to --2.