I have been using Derwent Watercolor pencils to do my watercolor experiments, and ended up buying two different types... the Derwent Inktense pencils and the Derwent Watercolor pencils... and because I really couldn't tell all that much difference between the two, I made a little chart, which looks like this:
These pencils are really fun to use and are very portable... just don't forget to take a brush and some water with you! For that, I recommend using a Koi Waterbrush, which is an empty barrel container with a brush on top. (See image below). This eliminates the need to carry around a container of water and a separate brush if you are traveling with your watercolors.
You can purchase these brushes from Paper & Ink Arts, one of my favorite art suppliers, especially for calligraphy supplies. And if you're looking for inspiration, this book,
written by a friend of mine, Janet Takahashi, is a wonderful source for information about watercolor, drawing, and journaling with watercolors.