Will a 35mm f/1.8 nikon lens on my d3000 be good for headshots?

Will a 35mm f/1.8 nikon lens on my d3000 be good for headshots?

Yes.

Depends. If you don't mind wide angle distortion then yes, otherwise then no.

35mm is fine for half body to group shots. Head shots will be more flattering using a focal length of 50mm, or greater, on your camera. This has to do with the distance from camera to subject. If you get too close, you will distort your subject. Unfortunately, the cheap Nikkor 50mm f/1.8 lens doesn't autofocus on your camera.

If you take half body shots, you can crop your image to get a head shot with minimal distortion. Experiment with your kit lens at different focal lengths and see what you get.