You can find the beginning of this post here - How to develop a good scraper on Perl - Lesson 1

2. Treebuilder class allows you to convert html page to the tree structure and perform the operations with the tree nodes like searching, walking through the nodes etc. If you will add XPath support to the Treebuilder class, you will get very powerful tool for html parsing. Look at the example below.

use HTML::TreeBuilder::XPath;

#create treebuilder object and parse the html code from content variable
my $tree = HTML::TreeBuilder::XPath->new_from_content($content);

#find all nodes 'div->h1' in the tree, div node must have 'class' attribute
#that will match the '/details\d+/i' regular expression
if (my @name_nodes = $tree->findnodes('//div[@class=~/details\d+/i]/h1')) {
  #get the trimmed text value from the first result node
  $name = $name_nodes[0]->as_trimmed_text;
}

You can find the full documentation here: a href=”http://search.cpan.org/~petek/HTML-Tree-3.23/lib/HTML/TreeBuilder.pm”>HTML::TreeBuilder, HTML::TreeBuilder::XPath

The books I recommend: