How to Prune Roses
On established roses, cut out poorly flowering old wood and saw away old stubs that have failed to produce new shoots, with the exception of climbing roses, prune all newly planted roses hard to encourage vigorous shoots. Roses send off suckers these should be totally removed, trace suckers back to the roots from which they grow and pull them away.
Lastly a few words about secateurs, I know you can pick up cheap pairs for less than £5 but they will not do a great job or last very long. Spend about £20 and get a good pair with a 10 year or even a ‘Lifetime' guarantee, they will make pruning jobs so much easier. Secateurs also come in many shapes and sizes, try a few to see how they fit your hand before you commit to buy them.
Keep dead heading for more blooms :o)