I found a great article on hair lightening -http://www.behindthechair.com/displayarticle.aspx?ID=762. It is written towards a professional audience, but it is still informative regarding techniques and goals when lightening hair for yourself or others. It also expresses some of the frustrations professionals face in their business, such as dyed brunettes who wish to go back to blonde! Now you know. A good read.

Thanks for the link, I really enjoyed reading that. It's nice to have those common problems solved in one place.