1994 Pontiac Grand Prix. Trouble starting

1994 pontiac grand prix. 3.1L with 115th miles. When you turn the key to start the car you hear a click coming from the engine but car does not turn over and when you turn the key back and forth a bit sometimes it catches and starts. Hasn't left me stranded yet but a bit of a pain playing with the ignition to get it to turn over. Has been doing this for about a month.