I've never found a tutorial. I'd still like to find one, but I did find a way of getting myself started on this, which you may find useful.
What I did was to open a new project with everything default. I then picked a few simple animations, with few frames etc., and basically copied it, frame by frame into a blank slot, looking to see how things were placed, working out why particular cells were chosen and not others. I noted things like which sound effects were used, how the flashes were timed etc.
Then I went onto the more complicated ones, where there are several cells placed into each frame e.g. Animation 60, Fire All 2 was the one I started with, and again copied them into blank slots. I noted how the multiple cells were placed within the frame etc. I then switched the default graphics for some of Timmah's to see how that affected things (quite amazing in some cases, total disaster in others) so that I could learn a bit how to choose which graphics to use.
That gave me an overall idea of roughly how it was done. But I'd still dearly love to see a decent tutorial on this.