Iyou
No luck with the avatar edit tutorials. The only one I could find was the one that you listed. :/
What did you have in mind for a more organized layout?
Yeah, I'm suprised I found the one I found. I was really looking on how to make pixel paintings of decent resloution, like the gaia items. That's as close as I got. I know that gaia actually doesn't allow you to put their avatars anywhere, but tutorials are protected by fair use because it's for educational purposes. Many people have no idea how fair use works, so they probably would rather not post them. That and people don't want to teach others so they don't have competition for their shops and such.
As for organization, I would make a thread if I could lock it or something. But yeah, putting them in different posts based on category. Categories can cross reference, but you kind of click on what you want like "hands" and it takes you to the anatomy ones, and the anatomy ones are listed aphabetically by specifics. For general, it can be listed as general.
The lists are getting long and they're kind of just there in the order that they were added. I will most likely be tutorial/resource spamming, so expect more. Anytime I find anything useful, I submit here.