I have found two things that have been very helpful in getting better results with my Nikon D70.
The first is a CD instruction manual called
The Complete Guide to the Nikon D70 I generally don't like photography books but this guy knows his stuff. I was very lucky to find it. He has many books on all varieties of Nikon cameras, none of which I have read. However, I would be surprised if they were any less thorough.
You can find it here-
http://www.bythom.com/d70guide.htm
The second item is called an Expodisc. You can place this over your lens and take a white balance reading instead of using a gray card. It's pretty cool. They can do a much better job of explaining than I can at-
http://www.expodisc.com/
I am not associated with either of these products, just spreading the word!