It's actually pretty easy but you have to plan it out.
Let's say you have three images and a back and forth button.
On your timeline place your three images. Space the images out, say at 5 second intervals and have each only visible for three seconds. Make sure that the middle of each sits on the '5' second interval (so at '5' seconds the image is visible for 4,5,6) and no images overlap, so that when you scrub the timer each image appears and then vanishes as the timer passes.
After you have done this, place three instances of each button and match the visibility of each set to that of the images, so that when an image appears, so does the set of back and forth buttons.
To make it all work, assign a 'go to' function for each button that commands the animation to jump to the next image. So for example, on image two (which is at 10 seconds), the forward button tells the animation to go to 15 seconds and the back button to jump back to 5 seconds.
This is a really basic way to get started. The system I have built up uses multiple timelines and lots of different images and select buttons. It took a while to set it up and make sure everything corresponds but once done, it works a template to create consecutive sliders for (i our case) different products.
I have to get back to this in the next week and we need to start rolling these out on our website, so when I do, I'll come back and tell more about how they were built up.
If in the meantime you have any questions, just let ask away and I hope I can help out.