Once a rose has bloomed, it should be removed, and the term applied to this procedure is called "deadheading". One should use pruning shears that are sharp in order to avoid tearing the cane as opposed to cutting it. Cuts should also be made at a 45-degree angle and about 1/4" above a leaf set.
Roses are deadheaded in order to prompt the bush into producing yet more blooms. The blooms should be deadheaded just as the petals are about to fall or shortly thereafter.
The first blooms of Spring will typically be borne on plants that are rather short either because the bushes were newly planted or because they were heavily pruned back in the previous Fall or Winter. In any event, one must remove the first set of spent blooms without cutting too far down the cane. A cut made at the second leaf axil down from the bloom will be sufficient to effectuate the removal of the spent bloom yet still leave enough cane to aid in the production of the second bloom cycle.
In subsequent bloom cycles, one can deadhead farther down the stem depending on the size of the bush. If the bush is a particularly tall-growing variety and one wants to control the size of the bush, a cut can be made several inches below the bloom.
Leaf clusters on roses either come 3, 5 or 7 leaves to a set. The first deadheading of the season will likely be made just above a 3-leaf set. Future deadheadings will usually take place just above a 5-leaf set, usually because you'll find many more 5-leaf sets than 3 or 7. The goal is to cut the stem far enough so that when the new growth eminates, you'll have a decent-sized cane. If you cut up at a 3-leaf set, the new cane emerging will be quite small. If you cut down at a 7-leaf set, you'll be removing a lot of cane because the 7-leaf sets usually occur far down the cane.
In areas where cane borers are present, it is also advisable to seal the new cut. This can be done by either painting nail polish over the cut or using Elmer's Glue.
By following these simple procedures, one can ensure repeat bloom cycles and have many more roses to enjoy during the course of the growing season.