Both www.liverdoctor.com and www.sensiblehealth.com has good guidelines on a liver-supporting diet - what to aviod, basically. Limiting flour-based products, citris fruits, bananas, blackpepper, is the short list. :)
Liver supporting herbs/supplements include:
Milk Thistle
Bupluerum (really gets rid of fat)
Dandelion
Chinese Gentien
Try to get an herbal compound with 2 or more, as herbs work best synergistically
MSM (small dosages as it acifies the blood)
B vitamin complex (all the B's help catobolize various things)
Lecithin - really helps take cholesterol/fats out of the bloodstream.