I have never tried stringwork and would like to give it a try. Does anyone know of any sites for instructions?

The Wilton books have info; I'm not sure about their web site. The important thing is to touch the first spot with your tip, then pull the tip towards you (away from the cake) about an inch or so as you move to the right; don't try to "trace" the area where you want the string to go--let it drop. It takes practice, so set aside some time.
Whether you use BC or RI, add about 1 t. of corn syrup or glucose per cup to make it a bit more stretchy.

There was an American Cake Decorating issue, April/May 2005 in which Cheri Elder gives great instructions on how to do stringwork. You may be able to order a back issue. My favorite tip of hers is squeeze your icing thru a nylon stocking to get out any tiny lumps in your icing that could clog your tip. It sounds crazy but it works!! I also purchased a book off of eBay that was on nothing but stringwork. Good Luck!!
Carrie