Using a wet saw is probably the best way to cut granite. A dry saw is just going to overheat under all the pressure and heat caused by cutting granite. You could have someone help you spray water on the blade as you're making the cut. If you don't have a person to assist you during the cut, just get a wet blade, and it will do the job just fine. Make sure that you are extremely precise with your cut and don't put too much pressure on the saw. Pressure will not only ruin the granite, but may also harm your saw blade.