Taking decent photos of the night sky with a digital camera is slightly harder than finding night mode. There is a fair bit of good advice on the net but it is mainly aimed at the use of traditional film in 35mm SLR cameras. Fast film, open the aperture right up and long exposures, even special film. Not that there is anything wrong with that.
The main checklist of important issue for the digital photographer are – 1) a tripod, to keep the camera steady during a long exposure, 2) a B (Bulb) setting (to allow extended time exposures) & 3) a cable release or remote control to avoid camera shake. Them maybe turn off auto focus and set the focus manually to extreme distance and maybe take off that UV or skylight filter. There are a few good extra hints and tips here.