Because watercolor paper is more absorbent than other papers, it does its best with techniques where water is used, though it's often used for colored pencil work as well! If you search our resources section HERE
you'll find over 70 ideas for using watercolor paper! If you're going to be stamping on the paper, be sure to choose hot press paper - it has a smooth finish that takes ink very well. The textured surface of cold press or rough paper makes stamping a little more difficult. Also, be sure your stamping ink is waterproof if you want to preserve it when you paint or add water to your image - a solvent, archival, or hybrid ink is best. For cards, I use Fabriano Studio Hot Press paper, and I buy the larger size (11"x14"), which can cut into 4 A2 bases and 2 5.5" squares. The best strategy for learning is to just play and experiment, and then practice practice practice!