A simple tutorial in making your own skin for Minecraft!
First download the default skin which you can find here.
Then, open this image in a photo editor such as Paint.NET or gimp.
Use the many tools to edit this skin, and when your done, save it as a .png image.
Go back to the www.minercraft.net site, goto your profile, browse and find your skin, and hit upload.
Congratulations, you just made your first skin, now go try it out in game!
Or, use this.