What are the best setting for shooting Skateboarding with my HV30?
Thank you..

Shoot in 50i/60i, especially if you want to do any slow motion in Post.
You can use a slightly faster shutter speed (I use up to 1/400th for shooting action sports) so you get less motion blur.

I don't know whether you already have a fish-eye, nor what your budget is.. but I use a Merkury wide angle lens. These are made out of a macro lens and a fish-eye (0.45x I think), which together make a 0.7x magnification. There seems to be no other way to attach the fish-eye to the hv than with tape, but the results are nice, knowing that it costs only 50 euros/dollars or so.