I'm writing an original fantasy/action novel involving magic, mages, etc...

[Angelblaze]

And I was wondering what type of descriptive language I should use, what other works should I study and get a feel for?

Harry Potter obviously is automatically on that list, but I want my work to have a slightly more Hellboy-ish/Constantine movie feel, especially since it has an intimate connection with hell - in a sense.

 

[DisasterSoiree]

The market is flooded with these genre-specific things. Go read Dostoevsky's Demons and write a modern incarnation of the tale instead, and you'll do well.

 

[Little Woodsman]

And I was wondering what type of descriptive language I should use, what other works should I study and get a feel for?

Harry Potter obviously is automatically on that list, but I want my work to have a slightly more Hellboy-ish/Constantine movie feel, especially since it has an intimate connection with hell - in a sense.

From classical literature-the Arabian Nights.
From contemporary fantasy-the works of Charles De Lint, especially The Dreaming Place and Jack of Kinrowan.
From comics-Neil Gaiman's Sandman & Books of Magic and as much of Alan Moore's run on Swamp Thing as you can find/get.

 

[Thaluikhain]

What sort of magic?

I've always thought that a knowledge of science would help with a fictional depiction of magic.

For example, in the old D&D, elves and so on could see in the dark, because they had, in effect, passive IR. Which means that they could see body heat, but other heat sources would confuse this sense. Certain other monsters had active IR, which means they produced their own IR light source to see by, so they could see things that didn't produce their own heat, but they could be seen by things with passive IR a long way off.

That's much more interesting than "sees in the dark well", and more consistent.

 

[Trinab]

Congratulations on starting your writing adventure.

You seem to be primarily concerned in the case of the tone of your narrative, and I think you answered your own question. There is no 'right' or 'wrong' form of tone, except in the execution of it. If your tone does not match the story you are creating, or is inconsistent, it will cause problems. I would say write your book in the way you envision it in your head, and worry about adjusting the tone in your revision so that it is constant throughout.

I know this post is somewhat vague, but a large part of writing is in finding your own voice and style. Much like art, at first you will be influenced by what you have read and like already. Don't try to write a book in a tone that you hate, because someone tells you that it's 'better.' Such things are quite subjective. Seek to tell your story first.