grinding = fun and easy!
My homecoming dance was the first time I freaked, and it was absolutely simple, well the basics for the most part. Next dance, the level of freak will be tuned higher, thanks to the DJ bible of course.
You just move your hips with the girl's along with the beat, and while she rubs herself all over you, you have the opportunity to feel her out with your hands.
Example: She's grinding her butt onto your crotch. "Omg what do I do next?!" Just place your hands on her lower back and side of the butt and dance, or something.
Example: You have your arms around the girl and she's grinding on you face to face. You can put your hands on her waist, neck, thighs, w/e. I'm going to try grabbing her hands and bring them up high, and I let go as I feel her body downwards in prom. Looking forward to it already =)
Overall, the whole grinding isn't too hard. Tango and Salsa is hard, but Freak can be done simply by moving your hips, following the beat, and getting touchy-feely; many things branch out from there.