Decide how you will be using decorative stamps. If you are going to stamp a design on a wall, you will want to buy sponge stamps. They are easy to load with acrylic paint and are available at most hobby and craft stores.
Contact a consultant who sells decorative rubber stamps. There are quite a few of these direct market companies such as Stampin' Up and Close to My Heart.
Use the proper type of ink when you are decorating with stamps. Dye based ink will dry quickly and is used on card stock or paper. Pigment ink is juicier and will not dry as quickly. The advantage to pigment ink is that it can be used on wood or fabric.
Take the time and effort to clean and condition the stamps that you decorate with. Cleaning the stamps with a special stamp cleaner is the best solution. Use a baby wipe with lotion to clean and condition the stamps if you don't have a stamp cleaning product.