Melee is just as importent as magic, if your oppenent gets with in melee range he will most likely use it(especially if you still have a bow or staff out) then jump back out and go back to ranged...rinse, repeat.

Since everyone can do everything then magic is you range damage and/or CC.

I highly suggest watching some of the pvp videos and really pay attention what they do and when they do it(look at there hot bar and see what it is that they que up). Then once you get your toon at a comfortable level start dueling people, those of your level and mid to vet players. You'll get the hang of it.