You don't say what type of roses you have, but this site has some great rose pruning info with pictures. If you scroll down you will see info on pruning the different types.
http://www.urbanext.uiuc.edu/roses/prune.htmlThis Australian site even has a video for pruning roses!
http://www.magicgardenroses.com.au/I'm sure others will come along with more info, but in the meantime you should be adding lots of organic matter to the soil to help them recover. A topdressing of an inch of compost would help them out. Roses (unless they are the old fashioned one) are heavy feeders. A topdressing of used coffee grounds will help make them happy too. You could make a compost tea spray for them this year and use it every couple of weeks to help them fight off fungal diseases. Here's how to make your own sprays for diseases and pests.
http://www.ghorganics.com/page15.htmlNewt