ok lets get started
To get a sum do this:
<xsl:value-of select="count($nodeset)" />
To ge a summary you can do this:
<xsl:value-of select="substring(@Title,1,100)" />
What the above does is it show only the first 100 characters of the title node
See some xpath tutotial here : http://www.w3schools.com/xpath/default.asp
Hope this helps
Patrick