Some know this already, others don't, but I have a YouTube Channel dedicated to a series of digital watercolor tutorials I've been making for Artrage-- the primary program I use for making realistic, easy to understand digital watercolor work. Here's an example of my first one. Bob Ross, we loved you! :D There was a lot to learn from that guy, and it's sort of what I aim for in a good tutorial.
So, back in August I was rather... ahem... under-employed, and decided to spend some of my time doing something "useful". So I taught myself how to use CamStudio and mapped out a series of tutorials. I wanted to give something back to the digital art community, as I've really appreciated the tutorials and things I've learned from over the last two years doing digital art. It would have been nearly impossible without the internet and the generosity of others-- for, as I discovered, making a good tutorial can take quite a while. So far, I have 11 videos up, and they total about 2 hours of run time. There's over 100 subscribers and juuuust about 10,000 views-- which is more than I thought I ever would have got. So clearly there's an audience for this, which is cool.
I have long felt that digital watercolors is rather under-represented-- there's a lot (of perfectly reasonable) focus on inking, comic art, and rough story boards, etc. All things that digital art does very very well, and which "pay". However, using Artrage I feel like I've been able to generate some interesting, realistic results while a) being mobile (as I use a tablet pc), and b) without ever having to clean up or prep. That's good news for a dad of a 4 year old.
So, these tutorials collate a lot of various info I've gathered over the last 2 years. They link to other tutorials and resources (sticker sprays, stencils, textures, etc), and I give credit where it's due. About 3/4 of the things I talk about I learned somewhere else and then synthesized and applied to the specifics of making watercolors.
I talk about things like-
1) Using Texture Overlays to generate realistic ambient watercolor effects
2) How to generate nice dry brush and wet on wet effects
3) How to use Layers to create transparent watercolor washes
4) How to create watercolor glazes over your grey tones
etc. etc.
I also have videos that go over the Artrage Pen-Only Toolbar that I helped make.