The most active Folk Club in SE London is the "Folk Mob", which meets in Eltham (Wednesdays - upstairs at the Tudor Barn, Well Hall Pleasance, Eltham, London SE. From 8:30 - 02088 543178). There are regular music/singer sessions in Sydenham and if you want to go further afield there is the Folk Club at Ruskin House in Croydon and various sessions at pubs in Woolwich and elsewhere. If you go along to a Folk Mob session (they are usually musicians and singers' nights with occasional guest artists) in Eltham you will make contact with people who can point you towards all the other folk venues in the area.