For very local listings, take a look at the SE22 Forum - it's more active and there's a jobs board where vacancies in this small part of the world are posted.
Otherwise, it depends what sort of thing you're looking for workwise. The Lewisham, Southwark, and Bromley council websites list vacancies to work within the local authorities and their partners. Sainsbury's at Dog Kennel Hill, Forest Hill, and Bell Green have community notice boards where people sometimes put up notices for casual work. If you're looking more for retail, hospitality etc in the immediate area, print out some CVs, put your walking shoes on, and ask in store if they're hiring. The All Inn One right by FH station is currently looking for bar staff, and it's a lovely community pub with great owners.