hadleyweed, there are many classes of roses. Within each class there are roses that grow in "bush" habit and there are those with "climbing" habit. If they are tall and upright, they are more than likely modern roses in the Hybrid Tea class (could also be Floribundas). Tea (no "Hybrid") is a different class, usually more flexible canes and rounder growing habit. Many people call the roses that you get from the florist "Tea" roses, but they are Hybrid Teas. Sounds trivial, but to us rose-crazed folk there is a big difference.

Before I could tell you what to prune, I would want to know if the rose is a once-bloomer or a repeat bloomer. If you prune a once-bloomer now, chances are that it won't bloom this year because you have cut off the canes that grew last year that will produce this year's bloom. This isn't a problem with repeat bloomers. If you want to wait until it blooms to give more description, that would be OK. You can always cut away anything that is dead or that does not look healthy and green. If you want to take a chance, you can cut them back by half, take out anything dead or diseased, also take out any stems/canes that are thin and twiggy looking (take a look at the overall plant and notice which are the stronger, thicker canes; the smaller canes won't be as productive).

Here are some articles from the Roses Forum:
What is your pruning Philosophy??

pruning confusion