Here are some free watercolour instructional videos from Stan Miller, a professional painter from Washington, USA.

These are links to the videos on Youtube:

1. Composition and Design Part 1
2. Composition and Design Part 2
3. Composition and Design Part 3
4. Watercolor Painting
5. Watercolor Basics Part 2
6. Watercolor Basics Part 2
7. Watercolor Basics Part 3
8. Watercolor Basics Part 4
9. Watercolor Basics / Portrait from Life
10. Doing a drawing for a Painting
11. Control your Brush
12. Control your Brush Part 2
13. Painting a Simple Watercolor Landscape
14. Three color watercolor landscape painting
15. Egg Tempera and Watercolor
16. Painting the Portrait
17. Watercolor Portrait / Hair & Skin
18. Portrait Backgrounds
19. Understand Value and Color
20. Understand Value and Color Part 2
21. How Colors Change
22. Choosing a Paintable Subject
23. Realism to Impressionism

Here's the compilation video made by my friend Drew Yu. He managed to cover places I could not go to.