My ash blonde hair:
Here's what my hair looked like before:
One Beyond the Zone bleaching kit later...
and after bleaching!
I thought this color was so cool, now I can't stand a day with it, lol.
Bleaching:
You can bleach your hair with any bleaching powder + developer (I use 20-30 volume now, the kit I first started with was 40 vol). Make sure to get both of the items! The powder usually comes in a tub, and the developer in a shampoo-like bottle. These two products can be easily found at Sally's Beauty Supply if you live in the US, or any other beauty supply store that stocks hair products, and shouldn't exceed $25 most likely. You mix the powder with the liquid developer as it instructs you on the bleaching bin, and you apply the paste you've created to your hair evenly, then watch the clock. This is important, because if you over-develop, your hair will be... well, over.
So be warned, once you bleach your hair, it will be a lot thinner and will break easier, resulting in split ends and can result in frizzier hair. Bleaching strips your hair, literally, which is why it can be stringy and like elastic post-bleaching. I feel that bleached hair requires more care and attention than normal, so only do so if you are ready for the time and commitment! If you don't take precautions with bleaching hair, many a time I see people ending up chopping their hair off to "start over".. I once have chopped my hair off to shoulder length to start a healthier phase of my bleaching journey when I had bleached it many a time. I hated it :P
It's a good idea to give your hair a rest after the bleaching and not add more chemicals to it for a few days or so, so it's not a bad thing to do this when you know you'll be home for a while. A deep conditioning session would be lovely for your hair, too! I have tips for bleached hair here!
Dying:
Now, after you've successfully lightened your hair, you can dye/tone it to the shade you desire. I have used both the boxed dye and liquid dye + developer from Sally's to achieve the ash color. I have used:
L'oreal Paris Superior Preference in 7 1/2 A Medium Ash Blonde - $9-11 USD
Wella Color Charm Liquid Permanent Hair Color - $5-6 USD
(I got it in 7# colors, such as the links below)
Personally, these results would last about 2 weeks before fading back to a brassier tone. Depending on how often you wash your hair, results may vary.
Good luck! (^-^)/