As Mike questioned, are you referring to spindle turning or face plate turning?
Here is a link to an avid turner and jig maker- Mr. David Reed Smith
http://www.davidreedsmith.com/Articles/OffsetTurning.pdf

For offset face plate turning, try Ruth Niles at http://nilesbottlestoppers.com/Pendant-chucks.html

Lew- Time traveler. Purveyor of the Universe's finest custom rolling pins.