What should I do to try to cut my dog's nails?

My dog feels uncomfortable towards a nail clipper & she usually tries biting me or gets real cranky. She really needs a nail trim because they are long & touching the ground. Any tips to cut an aggressive dog's nails? She was the same way towards the harness & brush until I took her out on the harness & after she knew the feeling of relief with her hair nicely combed. But it's hard to get near her with the clipper due to the fact you have to actually grab her paw...:/