if you are going to use some random rpm from the net and take the chance of really messing up your system
"el5" is for RHEL 5 .5 or CentOS 5.5
you need to use the "local install" option in yum
Please read the man page for yum or the help page
and i take it you did not read the error in your post
Parsing package install arguments
No package pdflib-lite-perl-7.0.4p4-1.el5.i386.rpm available.
Nothing to do
you did NOT install it .
BUT you should install from one of the software repos that you set up yum to use.
it it in the CentOS rpmfusion-nonfree repo
install the rpmfusion repo