Before you start, please note that english Is'nt my mother tongue. Thus, there are certainly some mistakes and nonsenses in this tutorial. I did my best, but st...
Absolutely a gem is that what I find here! Thanks for your effort in explaining the effect in detail and what I did not knew: There are three lights! At least something to start with! Almost fell of my stool. ;-p
By the way may I humbly add two more ways to create bumps. ImBatch allows to create normal maps from multiple files at once - producing so la la quality. But it runs fast and is something like my Swiss Army Knife with all the file manipulation functions. Then there is ssBumpGenerator which you can get for free at Sourceforge. Like imBatch ssBump Generator is able to process more than one file and produces nice results.
Hope that helps. Cheers!