Advice on bleaching hair? Or using lemon juice?

I have brown hair, with a black peek-a-boo, but lately I've been bored with my hair and I wanna change it up. I decided that I want to go blonde on top, but leave the black peek-a-boo and leave my bangs and the hair framing my face brown. I guess you could say that I'm scene, thats the type of hair cut I have. So I was thinking about bleaching the top half of my hair. However, I don't want it to be white. So I'm wondering what bleach will do to my hair, and like, what to use to bleach my hair. My hair is very very thin, pretty silky, naturally straight, and pretty healthy. The top half has been dyed twice, but the last time I dyed it was 7 months ago so its back to my natural color. So yeah, if any of you have advice, that would be greeeat.<33 Oh and I heard that lemon juice doesn't really work. But if it does, tell me about that toooooo:DDD