To start off, this is the single most comprehensive guide on the subject I've ever come across. Including chapters about brushes in Photoshop for Dummies and other similar books.

You cover all the bases and explain them well in both words and images. Your layout looks simple at first glance, but there are details such as gradients in the background and drop shadows on the screenshots that shows you've put some thought into it, and that leaves a clean and professional impression that matches the writing style.

I'm more a fan of a personal, conversational tone in tutorials because I find it easier to read them, but I'm really not sure how you personal you could get with brushes

That said, this is not a guide I will read from start to finish. I don't mean that in a negative way; there's simply alot of text and that makes it feel like an extract from a book - and, like a book, I prefer to skim through it once and maybe go back and read more thoroughly if I find an interesting part.

This made me wonder if perhaps a different format would suit your guide better. Like, cut each page in half so that there are six parts instead of three, and then put it together in Flash so that the readers could flip back and forth - just like a book. When the height of the images of the guide (got that?) is so tall, and there is so much text, I think it's would be easier to read if you split it up. Also there's no scroll option in Windows Photo Gallery Viewer (or whatever the name is) and I found it a bit tedious to drag with the mouse.

But that's my personal opinion. I don't mean that you should just go and cut the images and put that in the .zip instead, but that if you're familiar with Flash then you might consider an interactive alternative for your guide.

Apart from that, I can't find anything to put my finger on - it's a well-written and detailed guide and you've obviously put alot of time into it. I did learn several things which I didn't know before and that's always a good thing.

Keep it up, and thank you very much for sharing

Eil

ps: updating your tutorial in the gallery now.