Summarize the following:
Wait until the leaf buds begin to swell, then use a sturdy, sharp blade to ensure a clean cut. Prune by cutting at a 45-degree angle, just above an outer-facing growth bud. Growth buds are small raised or discolored triangular shaped areas on the rose stem. They are where the new stem will grow.  Pruning above an outer-facing growth bud encourages the roses to grow outward, rather than inward, which can reduce air circulation and lessen the visual appeal of the bush. Avoid pruning your new rose for the first two years after you have planted it. Your rose bush will only need to be pruned after it has developed old growth or mature stems. If you wish to maintain the same size rose bush each year, trim back about ⅓ of the plant. If you want it smaller, trim more, and for a larger plant, trim less. Cut this back until you see a healthy white center to the stem. Your aim is to have a plant where growth is well spaced out to encourage the flow and circulation of air. Remove close growing stems and any that cross or are tangled. On older plants you can cut back any old wood growth that no longer produces any new stems.

Summary:
Prune your rose bush in the early spring. Remove any damaged or diseased growth.