Recently I have shared information about watercolor paints and brushes.  Today I will address my favorite watercolor paper.  It is very important to use good watercolor paper.  Actually, it is very important to use very good watercolor materials all around.  I have seen beginning watercolorists become frustrated that they cannot achieve the results they want.  They blame themselves and and become discouraged with the entire process.  Many beginners scrimp on materials because they are not sure that they will continue with the medium.  But beginners are the ones who should invest in the best materials they can.  As a experienced watercolorist, I can make my way around inferior materials but it is frustrating.  Experience has taught me to solve problems and plow through to get the results I am looking for.  A beginner does not have the foresight or experience to realize that the problem is with the materials and not with them.  Watercolor paper comes in many sizes.  It is better to get a smaller size of a good paper than a larger size of an inferior brand.  Watercolor paper comes in single sheets, pads, or blocks.  Blocks are in a pad form but it is sealed all the way around so that it doesn't "buckle" when it gets wet.   Presently, I am using an Arches Watercolor Block, 140 lb.  cold press.  It has a bit of a "tooth" (texture) to it.  I I also use a pad of Strathmore, 140 lb.  cold press for practice and demos.  Cold press paper will have a texture and hot press has a smooth finish.  Strathmore, Arches, and Fabiano are good papers to start with.  Experiment with the different textures to see what you like from rough to smooth.