Tv Mode on Canon cameras, Shutter priority allows you to manually select your camera’s shutter speed. It is best to use this mode in night club photos because a trained photographer will know that Aperture priority (Av mode on Canon cameras) will hold the shutter open for too long and your photos will result in lens shake.
Hand shake will be an issue with night club photography as you are unable to use a tripod. However the traditional rule (on non-IS lenses) is that your shutter speed should be close to that of your focal length. For example if i was taking a picture at 18mm then my shutter speed should be about 1/20s. I beg to differ. I feel that the minimum shutter speed for a camera is 1/8s , yes… that slow. I tend to range my shutter speeds between 1/4 and 1/8, very rarely venturing as fast as 1/30s or even 1/60s for dancers, etc.
Dependant on your camera, and I am lucky enough to have a Digital lens without too much problems, the ISO rating you use should be set as high as possible. Trial and error is important because if you set the ISO too high, not only do you get a large amount of noise, but undesired lighting seems to ‘leak’ onto your subjects. I personally stay around the ISO 400 mark however ISO 800 is generally feasible, although skin tones degrade, I reserve ISO 1600 for pictures of the general crowd to make the scene more vibrant. I believe the ISO is heavily dependent on the camera and lens though as my good friend has a Canon 5D accompanied with an L glass lens, he prefers to shoot at ISO 100 (which would be near-impossible for me in low light conditions).