IF you can't afford the salon do this at home:
You want a 40 Volume Developer
(if you are lightnign your hair you want between 30-40)
and then a bleaching/Lightner Powder
and use a hair dryer to put heat on it so it takes in more and better!
or sometimes they have a kit their.
It also depends how BLONDE you wanna go, but someone should help you there as well. After you get done BLEACHING your hair use EGG WHITES as a deep condtioner/rinse out with COOL water not WARM, it works killer and beyond cheap. Just go to the Grocery Store and get some. But dont use the YOLK!