evlPanda said..I own one screwdriver, a shifter and a hammer.
You've got all the tools you need right there. Place the end of the screw driver on the spot you want to hang the clock, and then use your hammer to bash the screwdriver on the handle until you make a hole about 3 inches deep. Then go and buy a 3/8" x 3" coach screw and drive it into the hole with the shifter.
I wouldn't be too worried about some plaster coming off, the clock will cover that up.
As far as paintings are concerned, save yourself the trouble of making a hole, and just paint directly on the wall.