I have been interested in trying out MapServer and have no problem setting up a windows development box. Seems like all the MapServer implementations on Windows include Apache, php, mapserver, and a variety of other software. Unfortunately, if I wanted to use Mapserver in my production environment, I do not want to uninstall my functioning and stable Apache to replace with the packaged mapserver download. I understand that I can take pieces out of the package and use with my existing Apache but I would really like to have a clear set of instructions rather than references from 4 different websites. I am looking for clear instructions/how-to in 1 place.
I just found this, is it of any use?
There is the document "One Scotland: One Geography: One Information Network: Creating Scotland's Spatial Data Infrastructure: Cookbook 1 - How to serve a Scottish SDI and INSPIRE conformant Web Map Service" at http://www.scotland.gov.uk/Publications/2010/05/06161701/0
For your exact case e.g "make Mapserver works on an existing Apache", see http://www.scotland.gov.uk/Publications/2010/05/06161701/10
Here is something that may also help, its taken from the GVS, an open source web mapping solution from UNBC to help First Nationss collect information and respond to resource development within their respective area of interest.
EDIT: In the PDF link, there is a matrix which show how they have incorporated UMN Mapserver into their Apache configuration and going further into the documentation, how to set up the scripts to handle this exchange of information.