files needed
mod perl - http://perl.apache.org/dist

Download the mod perl source code to the working directory that you used for the previous components for apache and:
# tar -zxvf mod_perl-1.xx.tar.gz
This will decompress the archive and create a new directory "mod_perl-1.xx".
Now cd into that directory.
# cd mod_perl-1.xx

Configure mod perl and install it as a module for apache.
# perl Makefile.PL USE_APXS=1 WITH_APXS=/usr/local/apache/bin/apxs EVERYTHING=1
The above line is assuming that you did not alter the install path of apache. If you installed apache as an rpm instead of from source code, just change the path leading to "apxs" to the correct path on your system and you should be fine.

Compile the software
# make

Install the software
# make install

Add below lines to "### Section 2: 'Main' server configuration" in apache's httpd.conf file.

<Files *.pl>
SetHandler perl-script
PerlHandler Apache::Registry
Options ExecCGI
</Files>

if you configured apache with mod ssl
Move AddModule mod_perl.c above the <IfDefine SSL> block
Move LoadModule perl_module            libexec/libperl.so above the <IfDefine SSL> block