Henna website...authentic?

I think I'd like to henna my hair for the first time, and I've found one website so far that SEEMS like it's okay, but I'm not sure; does anyone know anything about this site? Have you ever bought anything from it, and how did it turn out?

It's at http://www.hennaforhair.com/

Or, if not, I would really love it if you'd point me to a good, reliable, etc. site that would be best.

My hair is dark brown, and I'd like red highlights, if that makes any difference. If you'd be good enough to look at this eBook (http://www.hennaforhair.com/freebooks/, I'd really love the dark brown "hennaed" hair on page 19. I'd really really appreciate any help to get my hair like that.

Thank you!!