classified ads script

Hi I need to put a classified ad script in my loca community site so that people can buy and sell all there old junk etc I would also like to be able do do something so that people could offer jobs listing and or post thier CV.
can anyone help me I am funding this my self and do not charge for my services so I need this as low cost as poss. I am not really adept with back end stuff so east to install would be great or if not something with very clear instuctions .
My server is supporting

perl 5.8.7
php 5.2.0
my sql 5.0.27

many thanks