While there will be disagreement among rose growers (surprise!) I've had the best luck for many years of spring pruning just as the lower part of the bush begins to green up. In your case, I'd recommend severe pruning. Rose bushes are hardy and difficult to damage by pruning. All of the wood, dead old stems should be removed, and all crossing canes should be pruned back to encourage air circulation and give better shape to your bushes. Additionally, I've had really good results in fertilization the roses by using the rose "spikes" one pushes into the ground around the base. One only has to do it once per season and the balance of the constituents is well designed for rose needs...