http://tilesettutorial.wordpress.com/
All the way to the bottom, you'll see categories... or if you want just go click on the previous posts.
I don't think that's a very good site to learn from. Especially for a person with a tutorial mindset. I'm talking about the - "I don't know how to do draw this (rock, grass, tree) so I will look for a tutorial on it how to draw it" instead of the more fruitful approach of learning from sources which will help your overall skill set holistically.
Yeah, I kinda worried about that actually. It helps some people get into it in the first place by seeing the methods other use to do a particular object, but yeah it then ends up being "copy this" instead of learning how you'd draw it on your own. Mostly I just do these for fun (Had a lot of free time back when I started this) or when someone asks me, but yeah I want to improve it as well because I kinda had a feeling that would pop up sooner or later. I'll definitely give it some thought, there are subjects I know that could be good to put on there that aren't just step by step things.
Anyway, thank you for this post and I'll think on it and see if I can get any other helpful suggestions for it. :3