I know this is a really noobie question. but please help me.

You don't is the simple answer..... Animation is bad, looks bad, and is not tasteful at all.

But.... if you STILL want to know then:
If you're using photoshop CS2 or lower, then you export the image to image ready and fiddle around there ^^ (never used image ready so I can't help you)
If you're using photoshop CS3 extended, then you go to window -> Animation. Then you duplicate the frames, hide what you don't want on certain frames, and tween the animation.

That's it in a nutshell, but there are some tutorials on this site. I suggest you search for them.