I know what your talking about with no time I go to work and come home with no energy sux

TV Mode and experiment with different exposure times a magazine I was reading suggested the best time is during dusk when you just have a little bit of light left you need to have the camera as stable as possible so perhaps use a timer so that way your hands don't cause camera shake if you like you can also use mirror lockup.
The hardest part is getting something to focus on in the dark also cover the viewfinder with your fingers if your doing a really long exposure to stop light going into the camera or use the thing that's included on the strap but you have to take the rubber eye thing off to use that so its a bit of a pain.