You will export all of your compositions and create one video story.
- Every slide must be animated, export each composition of your story as a quicktime or the YT movie file at 30 frames per second at the highest quality. Make sure you go back to each composition and mark your beginning and end on the timeline (shortcut is b and n).
- Create a new AE project file and a new composition labeled Video.
- Import all of your quicktime movies into this video composition as different layers and arrange them according to sequence. You cannot do this in Windows Movie Maker or iMovie because later you will need to insert many layers of audio (e.g. narrations, sound effects, background music).
- Post the video to posterous/YT (no audio).