Now that I have installed 4.4.1, can anyone point me to some good old fashioned manual instructions as to how best to upgrade it to the latest version.

  Im guessing that using this install utility, plus some simple upgrade instructions could easily become the best way for  server-administration-know-nothings like me.  Seriously, if there is an easy way to upgrade after the install, then lots and lots of people are pulling their hair out for nothing right  now.

Based on the site you pointed me to,  Ive been concentrating only on the steps for a development machine virgin upgrade, ie those necessary to upgrade the 4.4 install your setup program creates (without any additional modules, skins, config changes, or user data are added) to a 4.5.5 install.  It looks rather simple (maybe too simple?).   Basically it is saying to stop IIS, back up the web config, copy all the new install files over the old ones, and then copy back changes in the web-config before re-starting IIS and going to the site to force a compile.

However, Im not sure if all the items he says should be copied from the old web config are necessary in the virgin case. 

Clearly, the database connection strings need to be copied.  As does the db owner information.

OK, I did it, it worked, and it was particularly easy. 

The following may be of interest if anyone is in my situation,  a  newbie looking for a way to install the latest version of DNN now, before the next version of the installer is released.  This uses the source version and requires Visual Studio be installed, but Im guessing it could be done without using the source version, Im just too scared to mess anything up by experimenting to find out.

SIMPLE HOW TO INSTALL THE LATEST VERSION OF DNN
ON A LOCAL WIN XP DEVELOPMENT MACHINE USING  THE INSTALLER FOR VERSION 4.4.1 

STEP 1: Install 4.4.1 using the installer.  DO NOT INSTALL ANY MODULES OR SKINS YET.

STEP 2: STOP IIS 

     -- Here is how to stop IIS:
     1. go to your desktop
     2. right click mycomputer icon
     3. click manage
     4. expand "services and applications"
     5. expand internet information systems
     6. expand "Web Sites"
     7. right click "default website"
     8. click "stop"

STEP 3: MAKE A COPY OF THE 4.4.1 WEB.CONFIG FILE
    The site is at: c:/inetpub/websitename. This file is located in the root of your site's directory.  From now on we will call this copy "the OLD config file".

STEP 4: Download and unzip the SOURCE version of DNN
  (4.5.5 at this writing) into the website's directory  c:/inetpub/websitename

STEP 5: Go to the site's directory by going to:

STEP 6: COPY RELEASE.CONFIG TO WEB.CONFIG, AND THEN  EDIT IT BY COPYING THE FOLLOWING FROM THE OLD CONFIG FILE:

 CHANGE 1:
  <connectionStrings>
  ... COPY THE EVERYTHING BETWEEN THESE CONNECTION STRING TAGS
    </connectionStrings>

 CHANGE 2: Inside  <appSettings>:
     <add key="SiteSqlServer"  ... COPY EVERYTHING IN THIS TAG />

 CHANGE 3: Inside <system.web>:
      <machineKey ... COPY EVERYTHING IN THIS TAG />

 CHANGE 4: Inside <data defaultProvider="SqlDataProvider">:
       <providers>
   ... COPY EVERYTHING BETWEEN THE PROVIDER BEGIN AND END TAGS..,
        </providers>

STEP 7: RESTART IIS (see step 2 above).

STEP 8: Open DotNetNuke.sln in visual studio and built it without debugging, then run it.