How would one explain how a character is able to use lightning/electricity as a form of magic, I was thinking about friction with the wind, but i don't know if this is scientifically correct.
I guess you mean, what kind of scientific principles could the magic be manipulating.
I'd say, gathering electrons from the air around (or conjuring them from nothingness or other dimensions) and firing them at the target, possibly also draining off some electrons from the target to make it attract the lightning more easily. Any kind of air movement, or open skies with access to more air, might make gathering the charge easier, and I've always liked the idea that a lightning spell takes a little time to build up.
EDIT: The show Avatar has a description of lightning, but it doesn't say much about the bits of science that might be tapped into, except a note that for them lightning passes partly through the body and so needs a lot of self-control-- especially if catching and redirecting it. Not too helpful for a writer's basics, but you've got to love Zuko's learning it to dare the gods to strike him down. :cool2:
Depends on the understanding of the people witnessing it. If its modern day then elicricity works, but if its medieval than lightning bolt, maybe, or just raw energy.