Below is a list of my favorite supplies for painting with watercolors/gouache. Disclosure: These are affiliate links.
My Favorite Brushes
Princeton Neptune 4750 Round Watercolor Brush
Princeton Neptune 4750 Oval Wash Watercolor Brush
My Favorite Watercolor Paper
Legion Stonehenge Watercolor Paper Blocks
Legion Stonehenge Black Watercolor Paper
Paints
Aloha Watercolors - not affiliate, just my favorite handmade watercolors