Hello

I am kind of a newbie in editing video.

I wanna put a picture inside a video.
What I wan to do is put obama's face in a movie. So instead of Jack Nicholson's face there is a Obama picture; I wanna do the same with Hillary's face.
What software can I do this with?

Also, is there a way to move the pictures as the video goes.
For example make Hillary's face move side to side (like saying no) and the video keeps going at the same time.

Please,please help me.

Thank you : )