After Effects CS4

PDF (adobe.com)

Animation and keyframes

Editing, moving, and copying keyframes

Edit a keyframe in the Graph Editor
View or edit a keyframe value
Copy and paste keyframes
Edit keyframe values using a spreadsheet or text editor
Move keyframes in time
Move a layer duration bar but not its keyframes
Copy a value from a layer property that contains no keyframes
Change multiple keyframe values at once
Edit multiple keyframes in the Graph Editor

community help (adobe.com)