Tutorial (Part 1): How to Make Your Own Texture Pack

Making texture packs isn't actually that difficult. Really, all it takes is a good idea, and a knowledge of the tools you'll need to use to make it. This tutorial will attempt to teach you to use an open-source image editing program to make your own texture pack, from getting the files you need to using the available tools to make changes.

Setup:

Start by opening up Minecraft and clicking on the "Mods and Texture Packs" button highlighted above. This will open up your texture pack folder in Minecraft, and from there you can click on "Open Texture Pack Folder" to open it up in Explorer (or in MacOS, whichever you're using).

From the explorer, click the "Up one Level" button highlighted in the image. This will take you to your .Minecraft folder, which you'll need to find to get the textures out of Minecraft and into something you can use them with.

I trust you can navigate from the .Minecraft folder up to the .Minecraft\bin folder. Once there, look for the file "Minecraft.jar" and right click it (control click for mac) and extract it. I usually just put it wherever I want, but it's a good idea to put it somewhere other than the .minecraft\bin folder. You can also extract the files using WinRAR archiver, which allows you to go into the zipped file and explore without extracting the whole thing.






The files you can edit in a texture pack and expect to work with the built-in texture pack support are:
\Terrain (Sun and Moon)
\Mob (all the mobs)
\ Misc (There have been issues with these in the past; I know that Pumpkinblur.png works)
\Item (Signs, Doors - I'm not sure that the door.png does anything, Carts, Boats, and Arrows)
\GUI (all work as far as I'm aware)
\Environment (the snowflakes, raindrops, and clouds)
\Art (kz.png has all the art for the paintings)
\Armor (all the armor and the "charged Creeper" effect)
Terrain.png (The main texture file! All of the images used for all of the blocks are located here - keep in mind that objects are not blocks, and so the signs, mobs, carts, etc. listed earlier have different graphics)
Particles.png (portal effects, hearts & oxygen bubbles, sparks, fishing bobber, etc.)
And finally;
Pack.png (the image displayed when looking for your pack within Minecraft - this must be a square image and may need to be a power of 2 image [128x, 256x, 512x, etc])

Once you've located all the files you want to edit, copy them into a new folder (Give it a name that makes sense - for example, ME2005 texture pack_In Progress or ME2005 texture pack_Complete). It's important to make a habit of never working on the source files for anything, though if you mess up with Minecraft's source it's pretty forgiving (delete the Minecraft.jar and redownload it or re-extract your files from the Minecraft.jar). That way, if you make a misteak, a mess, or corrupt a file, you can always go back to the previous version.

That's the first step - getting all of your files in place and ready. The next step is downloading, learning to use, and actually using GIMP - an open-source freeware image editing program with lots of capability. If you already have Adobe Photoshop, or some other image editing program, the steps will be basically the same.

Of course, if you are either totally inept or totally lazy, you can just download the main images from this thread on Minecraftforum, kindly provided by Gestankfaust.

Warning: Do not use Paint! It doesn't work with Transparency, an important feature in many of the Minecraft texture files.