I am building this **broken link removed** . I am unsure though on how to connect the relay to a light(I am trying to build a clap on clap off light). The relay I got is a DPDT.
The circuit you attached does not make clap-on, clap-off. It would need a flip-flop circuit in addition to what it has to do that. It activates the relay whenever a sound is loud enough, then releases the relay when the sound is not loud enough.