I have stripped my hair.what is the safest way to bleach my hair?

At a hairdressers. This will be a costly endeavor and may take up to several weeks (depending on the colour/tone/level of your hair now) but you will get the best results possible. This will also be the safest application as it being done by a trained professional. This is when a hairdresser friend comes in handy.

If you don't have the money/don't trust a hairdresser/have a fear of salons then an at home bleaching kit is your friend. A friend that will destroy the ends of your hair and may leave you with bright orange hair, but will cost you very little and takes a few hours at home. If you plan on going this route, there are a few options.

The first is a salon-strength bleach found at beauty stores. Here in Australia we have Hi-Lift, not sure about what's available where you are. Ask someone at the store to advise you on the best product. These are a lot more effective but also a lot more dangerous, and the procedure for mixing a little tricky. You are required to buy developer and dye separately, plus rubber gloves, a measuring cup (preferrably separate from the one you use for cookies), a mixing bowl and an applicator brush. When mixing, you must use the right ratio of developer to dye (usually around 3:1) in order to get salon results. This bleach is usually very strong, in order to get the best results, also the mixing can be a worry when chemicals are involved. Probably the most dangerous procedure.

The other option is simple box bleaches. These come all set and ready for you to apply, no having to worry about correct ratios. Also, they come pre-packaged with rubber gloves and almost everything else you need. Their downfall is the quality of the product, and just how well it will react to your hair. This is not all that difficult and fairly safe.

Finally, for safety, it's really more up to you than the product. Remember to keep the bleach off your skin (apply it close to the roots but not quite touching) and if it starts to hurt, wash it off. Usually you will experience a burning sensation, but it's more a slight warming and perhaps a little irritation. Anything more than this and it's probably best to get it off.

Also, if you're applying at home, try to get a friend to help. Four eyes (and hands) are better than two and they can see the back of your head/find any un-bleached spots a lot better than you.