Making a video-animation using Photoshop, size?

[bahtsatang]

I'd like to make an animated video using Photoshop-created images. What size image should I use for video? And what option--PAL? NTSC? There are a lot of DV options. I don't want to use any DV footage, just make my own images, animate them in iMovie, and then upload it to YouTube.

Also, if you have any experience with this process, I'd love to hear some feedback, tips and tricks, that you can offer. :)

Thanks everyone, look forward to hearing your responses.