Sprite preparation.

I'm trying to make a game with street fighter-like animated sprites but I've got very little pixel art/sprite experience.

I want to know how I should prepare a file in photoshop to fill it with the artwork. Before I go any further I want to hear how other people prepare their files and animations.

I'm having trouble making sure the individual frames are uniform in presentation.

For example, one frame is slightly offset from another because it doesn't fit uniformly into the square relative to the other frames.

Are there any tips or tutorials you can point me to to work this out?

Thanks again!