The best time to prune roses is in the early spring while they are still dormant or at least not in a full fledged growth spurt. Generally, unless you see insect damage you should not be doing anything and then, if you see damage, the treatment depends on what's happening. If, for example, they get aphids, you can take care of them with an insecticidal soap. But, if it's something like Black Spot disease then you need to use a fungicide. If it were me, I would not do any treatments unless you see problems developing. For feeding, I prefer using a slow-release granular fertilizer designed for roses. You can buy this type of food at most garden centers or home centers."