Sammy,
I grew up in that area and fished the Lower Kings many times, it has been several years since I have been back. There was a large restoration project done and they continue to put trophy fish in there. Last time I fished it I caught a 5 lb. rainbow and from what I hear there are fish that are over 10 lbs being caught. Streamers are the way to go for big fish, but I use standard nymphs in size 12-16 range. It usually has great caddis and if you catch a hatch, dries are the way to go. The Upper Kings by Garnet dike is a long drive and unless you know the area or catch it on a good day it is very tough fishing. There is a public park called Avocado Lake on the lower kings that has a great stretch of river behind it. There used to be reports on this site, but you have to register for it first,
http://www.kernriverflyfishing.com/. Herb Bauer's sporting goods in Fresno is also a good place on information on the river.