Comments
I think the patience of the user is very important when it comes to documentation. I had cygwin already installed, so while I was downloading the files I was reading the cygwin documentation. However, I missed some important stuff. Anyways, my point is I think developers are lazy and don't usually take the time to properly setup an environment.
I am recommending rather then doing a step by step guide perhaps some visuals. lol. I'm not trying to bash your document, I just need to write something and this is the first thing I thought of.
An example of what I would do for configuring the environment :
Make the directory c:\mozilla and extract Performance Testing Zip as such:
c:\mozilla c:\mozilla\testing\...