Basiclly, I'm writing a story that incorperates magic and modern technology under one roof and I have a problem. Even though I'm writing magic, I just don't have a dahm clue what it is. I have two questions:
(1) In stories today, like the Dresden files, does it involve research in a specific area of magic or just made up?
(2) How do I go about research on magic?
As Yeratel says, there are an awful lot of different notions as to how magic works, in belief systems and in fiction, and it's pointless trying to please everyone or match all of them.
If it were me, I'd think about what I wanted my book to be like, what tone I wanted it to take - should the magic be grim and gritty and exhausting and wear eveyryone out any time they use it, which would be good in a
noir sort of setting where being exhausted goes with the territory, or should there be lots of it around in ways that feel more superheroey, or should it be numinous and mystic and spiritual, sort of thing - and then decide how to make it work based on what you want it to come out like.
Personally, I really don't like it when magic in books feels like somebody thinks that the D&D magic system is The Way Magic Works and I can almost hear the dice rolling behind each spell, but this is just me.