Check the ew classifieds and classifieds posted at your local supermarket (spinneys/geant) then start calling them up, start with a phone interview and the ones you are interested in set up a time to meet up for a personal interview. Either at a coffee shop, mall or at your house. Whatever suits you best. Be prepared for some candidates to not show up, come late (transport is often an issue for them) or to call and cancel last minute. It will take some time to find the perfect match.
If you only need someone to help out for a few hours, try a cleaning agency. Usually they send girls for a minimum of 4 hours per visit