Here are some links:
A slide show that is a good beginning:
http://nwalsh.com/docs/tutorials/xsl/xsl/slides.html
The wikipedia entry:
http://en.wikipedia.org/wiki/XSLT

XML/XSL are important to be able to receive and send information.

Here is a way to transform a Microsoft Developers Studio project: (remove te spaces betwwen the <

<?xml version="1.0" encoding="ISO-8859-1"?>
<xsl:stylesheet xmlns:xsl='http://www.w3.org/1999/XSL/Transform' version='1.0'>
<xsl:variable name="newline">&#xA;< /xsl:variable>
<xsl:output method="text"/>
<xsl:strip-space elements="*" />
<xsl:template match="VisualStudioProject">
<xsl:value-of select="@Name" />
<xsl:text>&#xA;< /xsl:text>
<xsl:apply-templates/>
</xsl:template>
<xsl:template match="Configurations/Configuration">
<xsl:value-of select="@Name"/>