Try this link for some good realistic glass settings. Its failry simple to understand just read through slowley.
http://www.geocities.com/CollegePark/9315/lw/tip4.htm
One thing to remember about glass is, that it is realistic with good settings but you also need an environment around it to reflect and refract. An good environment around it will help a great deal in its realism. Try modeling some simple items to place behind or around the glass object. HDIR maps make good refraction and reflection environments. Also a Very slight bump map procedural will help a bunch.