I am a firm believer that you do not have to have all the best supplies or the supplies I have in order to learn watercolor. I use a mixture of inexpensive and more expensive supplies depending on what is the purpose of my painting.
Watercolor Paper: 9" x 12", 140 lb, Acid free, Cold press, Academic level 1
* Watercolor Paper makes a huge difference - it doesn't mater what brand but it does matter that is 140lb paper.
Angora 36-Pan Watercolor Set or 24-Pan
* I have been known to even use simple Crayola Watercolor sets you can find in the children's section of stores. You do not need expensive watercolor set to make a good watercolor painting. You will find that the more expensive the watercolors the more pigment they have and brighter they are. This set gives a good collection of color that is inexpensive.
Uni-ball 207 Impact Gel Pens, Bold Point, Black, Box of 12
* My favorite pen! I use it for everything, once it drys it is permanent.
Faber-Castell Kneaded Eraser, Large, Grey
* You can find kneaded erasers in most drawing sets or in the drawing section of craft stores.
Princeton Select Synthetic Brush - Round, Short Handle, Size 2
Princeton Select Synthetic Brush - Wave Oval Mop, Short Handle, Size 1/4''
Princeton Select Synthetic Brush - Liner, Short Handle, Size 10/0
*These brushes are my go to brushes and I use them on every watercolor I make.