Help With Sprites

As my first game I'm planning on making a Halo RPG but when I load the sprite sheet I made using base sprites from:

http://twich14.tripod.com/sitebuildercontent/sitebuilderpictures/minichieffinal.gif

but whenever I load them into RMXP they look really choppy and jerk about.

How can I fix this?

here is the sheet:
(tell me what you think, the ones i edited probably aren't that good so tell me what to improve.)



Thanks in advance.

I use 2k3, but I have used XP a little. Wat you should do is look for specifications for images, look at sprites, and make a image template in MS paint with a grid on it, each line is a multiple of watever amount of pixels is allowed. So, if you have a 480x480 sheet, and each square can only be 96x96 pixels (this is for the 2k3 animation sheet. Don't use these) then you would have a sheet with a 5x5 square grid, where you could put your sprites. Oh and be sure to center them or they won't look right. This can be hard, but even I don't got a good method for centering stuff. Kool chief sprite btw.