This question and answer apply to Minecraft 1.4.7 and earlier. Minecraft 1.5 and later support high-resolution textures automatically, and do not exhibit the misplaced animations described below.
Minecraft versions before 1.5 were not written to support different-resolution textures.
The default Minecraft terrain texture in these versions is a 256×256 image with 16×16 tiles in it (a texture atlas).
The code which animates the animated textures in Minecraft (fire, water, lava, and portals) writes onto specific pixel offsets according to 16×16 tiles, which are wrong for larger textures, so you get small fire/water/portal images occupying other blocks. Presumably the patchers replace the 16× factors with 32×, or whatever fits the actual texture resolution.
The reason the textures mostly work is that the OpenGL 3D API used by Minecraft mostly takes coordinates in textures in terms of numbers between 0 and 1, rather than 0 and whatever the pixel size of the image is, so the main rendering doesn't care; only the animated textures, which are actually defined in terms of recalculating individual pixels and modifying the data of the texture in memory, are affected.
Also, tiles over a certain size (128×128, I think) will crash Minecraft. Below that size, you can still use HD textures and it will work except for the misplaced animations. The animated items will not animate, and (for a 32× pack) these will have animations on them: bricks, gold blocks, Netherrack, and pumpkins.
Ok, so this will be pretty hard... anyway so, I'm just gonna tell you what I'd do.
So first I'd get a copy of the default Minecraft resource pack. Then when you go into the folder just change the textures and such.
Some warnings:
One, Being that some blocks such as grass use special textures, Just drawing all over it will look odd and not look how you want to all the time. (depends on what colour you want it.)
Two, tying to make costume sounds will be very hard. Since 1.7 they changed the way sounds work. However there are ways to fix this, there are some programs that will do this for you. But that is known be a little hard!
Three, When you have finished the resource pack remember to put it into %appdata%/.minecraft/resourcepacks then select it in game. and start game and test it out!
Oh and if you look hard enough you will find every thing you can change, E.g the image that comes up when you put on a pumpkin, or the look of a enchanted item. (the purple flashy bits.)
Hope this helps somewhat, But if it didn't then... i have my excuses, My first post :3
Oh and i was just tying to say everything that might help. since as i don't know how good you are at it at all so i just acted like you needed to know!
Best Answer
The following is the mapping of the texture as found here
I found it with a Google search for minecraft creeper texture template