Question
The rose bushes in my yard were not properly trimmed for about 2 years. Now they look like round shrubs.  Where do I start trimming? Is it ok to cut them down to the ground or should I thin them out somehow?

Answer
I am assuming here that you are talking about roses that are hybrid teas. The reality is that roses do not have to be pruned every year so don't worry about not doing it for two years. The roses will not suffer at all from not being pruned. Don't cut them down hard as this puts them under stress. It takes a lot of energy to grow back again. Cut them right across the bush down to about a third. Don't worry about how or where just cut them down a third. Then cut out any dead or diseased canes. Cut them back until the insides look a nice pale green. Finally cut down to the base, canes that are thinner than a pencil as they will never be strong or grow good flowers. That will be all that is needed for this year. Cutting a rose back too severely will put them under stress and the roots will shut down until they recover in a few weeks.