Magic should probably be only learned by people born with the abilities to become a mage, and the typical races who would have magic, like dragons. 

I think it can be learned, but if you did not already have the power within you, than no go.

So it should be like Gandalf, but not as limited. You could say 1 in 100 or so people might be born a mage (for all races) Races like elves might have a higher rate of their kind being born with the ability. 

Fairies and the like would have their types of magic, of course.'

But it wouldn't be like Harry Potter where the mage can practically do any type of magic. Each mage would probably have one or two things they can do really well? And there might be a few every however many years who are born being a little more powerful?

What's your opinion?