coloring your hair yourself.

i'm looking into buying a bottle and dying my hair permenent by myself, but I have some questions.

What's the best amount of time to leave the color in before you wash it out? Should I always let the water run until it goes clear? Does that make any difference? Is dying your hair yourself any good? Because I don't really want it to fade, and I want to make sure I put it in right without stuffing it up. Does anyone have any tips on dying your hair yourself? Like how you should put the dye in? I've put 6 week colors in before, but I'm scared about putting permanant (sp) in now, so i want to make sure it all goes good.

If you are going to make a habit of dying your hair yourself, its better to know the color wheel and get your dye at a beauty supply shop instead of buying boxed colors.  The base in the dye is important in getting more predictable results and they don't tell you what the base is in boxed colors (the boxes you buy at walmart or the drug store that is...That's not to say you can't get good results from the box, just that its more difficult to predict).  The base color is written on the dye you buy at beauty supply shops.  You will also need a bottle of developer and a plastic squirt bottle to mix and apply it. 

Here's a site with a description of the color wheel as related to hair dye. http://www.geocities.com/HotSprings/4266/color.html