I am a medium brown naturally but recently I have used permanent hair dyes to go to a blonde stage it has worked somewhat but then I added highlights and now I'm wanting to go all the way. My hair is now a light golden blonde with lighter blonde highlights and it wont except color in some spots i went to a beauty supply place and they told me to use a protein filler before i do any more coloring will this work. Also after all the dying my hair is still healthy and shiny I do deep conditioning every other day.
While the conditioner is important, it doesn't actually repair the hair. Its primary function is to prevent mechanical damage to the hair and to make it manageable (it feels better).
Shazmataz' way of doing it is not bad, except that you're already mostly there.
I recommend double-processing - bleaching and toning. But since you're already substantially blonde, do only the roots and you'll become blonde as it grows out. Besides that, you won't have the problem of sudden change that often causes people to question whether they've done the "right thing" (and sometimes they then make a huge mistake and throw dark dye on the hair). If you can pick out darker strands, you can lighten them also, but be careful not to over-process the already-bleached strands of hair.
Another possibility is to do "tone-on-tone" (lighten with single-process haircoloring to dark blonde; bleach highlights).
Here are some good forums for blondes:
Bottle Blondes Board (http://www.network54.com/Forum/503669/)
The Going Blonde Message Board (http://www.network54.com/Forum/127834/)