If you are a complete beginner then I recommend you start with the "1 Brush Method". In this free course, there are about 11 lessons in which you paint every different kind of scene - so from snow scenes and country scenes to sea scenes and buildings. In this course we will use only one brush and one color so it is an easy and simple course for complete beginners that develops your brushmanship and your ability to get your mixes right (which most watercolor students fail at) and your tones (which is one of the most important things in watercolor painting). The "2 Brush Method" and the "3 Brush Method" build upon what you learnt in the "1 Brush Method" but now we are using more brushes and colors.
Soon there will also be lessons sketching and composition as well as soon fun experimental things you can do with watercolor painting.