One big problem- Photoshop is a photo-editing software, not a video editing software.

Unless you plan to make only small GIF-animations, you should consider something else like Zwei-Stein, Avedit, or Avidemux.

A list of free software to get you started: http://tv.isg.si/site/?q=node/873 (Zwei-Stein is in there too).

For something a bit more Anime/drawing/cartoon-related, try http://www.aniboom.com/ShapeshifterMain/ or any of the programs mentioned at: http://animation.about.com/od/referencematerials/a/ freesoftware.htm