Lets say you want some leters on stage which you want to animate which zooms in from the left,  one at a time. So selecting the text tool, type BEST WEB on stage and selecting all the letters press Ctrl+B to break them apart,

then distribute to layers by going to modify menu, timeline and distribute to layers. In your time line you will see that ‘BEST WEB’ each letter is distributed to separate layer as seen below.

Lets say we want all the letters to animate to stage, go to frame 6 and hit F6 to insert  keyframes. Now go to frame 1 select all the letters and put them all together in one place, by going to the window menu bar and click on align and squeshing them all to gether.

you will see something like the one below, don’t panic

And take this entire letters which is squished up to the extreme left by pressing shift and dragging them out of the stage. Now we are going to animate the “BESTWEB” on to the stage, so click inbetween the frames in all the layers and create a classic tween. Now when you run the movie clip you will notice that all the letters come on to the stage together, this is not what we are looking for, we want the letter ‘B’ to come in first, then the ‘E’ then the ‘S’ and so on. We do that by selecting all the keyframes in each layer and pushing it further away from the previous letter like the one below;

This is done so that the letters are staggered, that the ‘B’ comes in first, then the ‘E’ comes in next, then the ‘S’ comes after that and so on, when you run the movie clip at this point, you will see a problem that when ‘B’ comes in first and as the ‘E’ comes in next the ‘B’ starts to disappear, that is because the letter ‘B’ ends at frame 6, this will happen to all the letters while you animate because when the previous one ends the next one begins.
To fix this problem we have to go the the very last layer ie: ‘B’ layer here and insert blank keyframes to all the layers. We do so by clicking and dragging all the layers from the last layer upwards and pressing F5 to insert frames like the one shown below.

If you run the movie clip by pressing Ctrl+Enter you will notice that the letters land on stage one at a time in a proper sequence, that’s it you now know how to do complex text animation in flash CS4.