Does anyone know how to configure a PC so that it shows the mouse pointer in screen shots when using the Print Screen function?

There are a number of screen grab tools on the market that are ideal for writing guides. Screenshot Captor is a freeware (donation requested) product which is great for simplifying and speeding up lots of screen capture processes: http://www.donationcoder.com/Software/Mouser/screenshotcaptor/index.html

Another option is SNAGIT (from TechSmith). The version I’ve got has CamStudio bundled in, which is a user friendly way of recording screen movement into little video clips that records series of movements on screen and you can add a highlight halo to your mouse cursor to make it even more visible. You may find CamStudio useful for either creating short training videos for your website or perhaps creating screen grabs from your videos. A free download of CamStudio can be found (along with a vast array of other free tools for learning and teaching) through the RSCs AccessApps and scrolling down to presentation tools:
http://www.rsc-ne-scotland.ac.uk/accessapps/compare.php