Just I few tips ( I dye my hair regularly- it's currently a beautiful shade of After Midnight Blue )For shorter lasting color:
-Use SEMI-perminent
-condition your hair before and after dying it. The if it has the propper ammount of moisture it will be less susseptible to color
-Do not blow dry your hair while the color is setting even if the box reccomends it

Remember to line four forehead and ears with vasaline so you don't end up scrubbing the black dye off, and of course, have fun!