Here are some of the shortcuts that I use when working with video in Photoshop CS6:
• Tap the Spacebar to play the timeline at the current time indicator point. Tap it again to stop playing.
• Option -click (Mac) | Alt -click (Win) the current-time display in the lower-left corner of the Timeline panel to switch between timecode and frame numbers.
• Option -click (Mac) | Alt -click (Win) the disclosure triangle next to the layer name (on the Timeline panel) to expand/collapse the list of layer animation options.
• Shift-drag to snap an object (keyframe, the current time, layer in point, etc.) to the nearest object in timeline.
• With multiple keyframes selected, Option -drag (Mac) | Alt -drag (Win) the first or last keyframe to scale the time “between” keyframes proportionatly.
To enable the following shortcuts for video, use the fly-out menu on the Timeline panel to select “Enable Timeline Shortcut Keys”.
• Up Arrow moves to In Point of the current layer. Down Arrow moves to the Out Point of the current layer.
• Left Arrow or Page Up moves to the previous frame, Right Arrow or Page Down moves to the next frame. Add the Shift key to move 10 frames at a time.
• Shift + Up Arrow moves back in time 1 second, Shift + Down Arrow moves forward 1 second in time.
• Shift -clicking the Next/Previous Frame buttons (on either side of the Play button) jumps to the next/previous whole second in timeline.
• Tap the Home key to jump to the beginning of the timeline, tap the End key to jump to the end of the timeline. Note: on a laptop, press the function key (fn) and use the Left/Right arrows to jump to the Beginning/End of the timeline.
And don’t forget, you can create custom keyboard shortcuts for any of the items on the Timeline panel’s flyout by selecting Edit > Keyboard Shortcuts. Choose “Shortcuts For: Panel Menus” and scroll down to Timeline (Video). Use the disclosure triangle to view the individual commands and apply your own custom shortcuts.