I realised that the first version of this was totally out of date, faulty, and not really comprehensive. So, since so many people ask me what paper, brushes, paint I use, here is the answer!
Part 2 (Painting basics) is here: [link]
Part 3 (Tricks of the Trade) is here: [link]
For a more in-depth look at different types of watercolour, see here: [link]