Gag-inducing girly question - I want to dip dye my hair, how do I do this/what should I use?

Specifically, what brand of bleach should I use, any specific techniques anyone’s used that worked well? Scoured the internet but can’t seem to find specific info . . . I know I’m being terribly trendy, but I’m bored and I don’t want to get a cat or a piercing.