My first animated GIF was created in Macromedia Fireworks circa 2000, After that I used Adobe ImageReady/Photoshop, and have been through several version changes in Photoshop. In CS5 it was Window>Animation, in CS6 it is Window>Timeline. You get a drop-own choice between Create Video Timeline or Create Frame Animation.
Click the "Create Frame Animation" text to set up first frame. At the bottom of the Timeline choose how many times to loop animation, and below each frame use the drop-down arrow to select how long frame should display.
Duplicate frame, and turn layers on/off or otherwise alter display for animation.
I hope to attach screen shots hereto to illustrate the steps.