Cables and Adapters
Once you get your equipment to the location where you'll be playing, the next step is to get it all to work well in a foreign environment (read: not your living room). Here's a list of items you'll need to ensure that you're able to play when the moment comes.
A microphone cable to connect your mic to your amplifier or effects. If you're going to be standing far away from your amp you might also need a microphone extension cable.
A heavy duty extension cord for your amp. Most amp power cords are only about six feet long, and the nearest plug might be farther away. Also recommended — a couple of three-prong to two-prong plug adapters and an extra plug with screw terminals for your power cord for that wonderful moment when your plug gets severed right before you're supposed to begin playing.
An extra fuse for your amplifier. Fuses don't blow that often, but when they do it's a show-stopper.
If you play through a high-impedance microphone and you want to plug into a low-impedance PA system, you might need a direct box that accepts your mic's ¼-inch plug and comes out with a three-pin balanced output jack