Bah...for the cat behavior experts and those with cats...

I have a cat just out of kittenhood and he's developed a bad habit of biting and scratching when you try and pet him. He's jumpy about being touched suddenly which I think goes back to when I rescued him as a kitten one night from two big chow dogs that were trying to kill him. I've tried the taps on the head and the water sprays. I had hoped he might calm down once he had been neutured but that doesn't seem to have worked either. I don't want to give him away so any suggestions from the cat lovers on how to curb this bad habit of his and reinforce good behavior?