I have fully blogged my Henna experience, you can click the link (in my sig) but you might have to scroll down a few entries.

I will NEVER go back to anything but henna.....it is very different from chemical/hairdresser/home colour, but in a really good way. Yep, it's like applying mud (or horsepoo lol) and the only thing you have to be wary of is "Black Henna".

I googled 'henna for hair' and there is a wealth of information available. Apparently it's excellent for covering greys.

ETA - I'd rope in a GF to help you if you haven't dyed your hair at home before.

ETA2- here is the link, it was a page or so down... http://lulu-unperfectlife.blogspot.c...mical-dye.html