In answer to the questions posed, and most of you seem to ask about the same thing, I'm going to tackle the most popular subject first. The questions boil down to the following...
1/ WHAT DOES AN EDITOR DO?
Depending on the circumstances it might almost be easier to tell you what an editor doesn't do.
If you're at a larger company an editor's role will be different to a small company. In the Big Boy Network you have Publishers and Editor-in-Chiefs dealing mostly with the overall direction the titles are going in and deciding which creative talent does which book, so the Editor has to be the one to make it all run smoothly once those creative teams have been put in place. You become the diplomat, the best friend they never had and often you have to convince everyone to make compromises based on what promises each creator has been promised. Was the interior artist promised he could do his own covers but you've been told by the publisher to find another artist? Was the artist promised that he would be co-plotting the stories or at least getting 'meaningful' consultation with the writer and editorial on them?
You are the guy that has to make sure the creative teams deliver something they are happy with, the publisher is happy with, the fans are happy with and it all has to be delivered on time. Remember, you are usually the guy who is working 9-5 (ish) and gets weekends off. Your artists usually need a full month to do the interiors of a book with very little time off, if any. So when you ask for changes or need something early you need to be able to understand what they've been going through.
If you can't spell and have no ear for when a writer is writing dialogue-using accents (something spell check has the automatic need to want to change), this isn't a career for you. Understand also that you will be reading the same comic several times before it gets printed. There are outlines to read, first drafts, artists draft, lettering draft (always offer the writer the chance to rework dialogue once the art is complete as it may change slightly), the actual lettering, production proofs to make sure the most current files were compiled in production and that the Illustrator files didn't change when merged with Photoshop files, making sure that the artist has drawn all the costumes and that everything has been colored correctly, day is day and night is night, and of course that all the pages are in the right order. I have seen comics where the same lettering file was used twice in the same comic by mistake or a balloon was forgotten making things a little confusing.
I should point out now that you won't be just editing one comic. Chances are you'll be editing anywhere from 4-12 titles depending where you work. Just because Marvel make so much money on their movies don't think for a second that money trickles down. Marvel editors are probably the most hardworking and have the longest days in the industry.
Depending on the creator you are working with your control over their work will vary. Back in the 1960's Marvel's EIC Stan Lee had a reasonable degree of control, but his co-creators had a lot more control. Stan would call Jack Kirby to discuss the next issue of the Fantastic Four where Stan's only input might be "use Doctor Doom again"; Jack Kirby would then create the story including a lot of dialogue suggestions. When the art came back Stan would just have to make the story work and dialogue it the way he felt was best. Not ideal, but it created some of the best comics in America over the last 60 years. Sure he was working with Jack Kirby who almost single handedly built the Marvel universe, but that way of working can be very creative and yield great results IF you have the right team. It's a way that DC comics are using very much now and allows the editor and publisher to have more input before the final product is complete while not making the writer redo full drafts of the scripts.
At smaller companies you may also be doubling as a production manager, designer, copywriter, and dealing with more titles that have much lower budgets. Trying to get creators to turn in work every month for very little money is incredibly difficult and challenging. Especially when you might not be getting much money either.
Remember that most people are in the industry are in it because they LOVE it. Your main task is to not break their hearts and make that change.
I was originally a comic artist and inker so I have a better understanding of what it is I am asking an artist to do. Knowing as much about the process as possible will help you and it's also probably why so many editors go on to become writers.
2/ HOW DO I BECOME AN EDITOR?
Write, call, email, and check out message boards looking for internships. Many companies use them, the smaller the company the more they'll probably use and the chances of getting some real experience. These when you can get them are solid ways of getting experience and for the publisher to get to know you. I would estimate that most positions are filled with people that have worked for the company doing internships. You won't instantly become an editor either; there are many stages along the way including proof reading, being an assistant, helping with mailing submissions and artwork back (although most artists email their work now).
But before thinking about becoming an editor, think about why you want to become one. Many see it as a way into the industry so they can eventually become a writer. The job is not glamorous and can often be thankless. At the end of the day the credit will fall on the creative team, the publisher and the title itself. You'll probably get the credit if something goes wrong. A good editor is one that, like a letterer, no one notices because you're doing your job.
3/ WHO WOULD BECOME AN EDITOR?
This is a question you have to ask yourself. Why would you want to become a comic book editor? Do you want to be a publisher and editor is just a step along the way?
First off, you HAVE to love what you do and the industry. If you've never read Batman don't go looking to DC for a job editing the character. It just isn't going to happen.
Do you know what? If you have to ask yourself this question it isn't for you.
4/ WHAT ARE THE HOURS WORKED?
While I do know a few editors that can get away with a 40-hour week, they seem to be the very lucky ones and they're corporate workers.
If you're like me and freelance working on corporate, private as well as your own projects, there is no time off. You're available 24/7 and loving it. I'm very fortunate to have family that understands that and we're adaptable to one another.
The comics industry is run by people who mostly love it. It is not for the fair of heart. Hours are long and rewards can be few. If you can live on mostly the satisfaction of a job well done and comics, then this MIGHT suit you.
5/ GOOD VERSUS BAD HABITS OF EDITING.
Good habits are listening to what everyone wants and striving to make everyone happy while not letting the quality of the work suffer.
LISTEN, LISTEN, LISTEN!
Never point out a mistake or something that doesn't work without coming prepared with several alternatives. Seeing something is wrong is easy, but a good fix that will make everyone happy? Priceless.
If you are asking your creators to go the extra mile support them that extra mile. They will often rely on you to stand up to your superiors. Be prepared to argue your points. Don't give in easily because creators talk to each other and if you're a good editor other creators will know. That will make it easier for you later on in your career when you reach out to these creators to work with you.
Also remember to treat every creator equally as much as possible anyway. Just because the creator you are working with today isn't a huge name doesn't mean they won't be tomorrow. Creators are like elephants. They never forget. Especially if you were a dick.
But the most important thing you can do as an editor is make sure your freelance talent is paid on time. Make sure you get those invoices in ASAP and don't sit on them.
Bad habits? Being lazy, not listening, trying to steer other people's projects in the direction you think they should go in, trying to get writing assignments from other editors by offering them assignments in return, relying on spell check, leaving freelancers hanging over the weekend... Just don't try and be that person.
6/ HOW DID I BECOME AN EDITOR?
Well I never trained for it. I trained at college doing printmaking and illustration. I always loved comics and hoped that the illustration training would help, which it did, kind of. I always did well in English, particularly creative writing.
After a couple of years in the industry I quickly realized that my dream of writing and drawing my own strip was only going to happen if I did it myself. I also realized that self-publishing is like going to the gym, the pain and the gain is better when you do it with someone else.
My friend and brilliant artist Garry Leach was interested in doing something with me. We came up with a title (Skit City) and set about developing our own ideas. When in the pub at comic conventions talking to others we were quickly met with the same response, "Publishing your own comics? Creator owned? Can I do something?" Our 32-page comic suddenly became a 100-page behemoth that needed to be designed, printed, marketed, solicited and, of course, edited.
The title changed from Skit City to A1. We felt that an anthologies title shouldn't give people any preconceived notions other than quality, so "A1" fulfilled that very well.
As A1 continued and gained momentum, I was increasing sort after to do something similar for other publishers. I took over and increased the circulation ten fold on the UK art and music magazine Deadline. I launched another UK magazine Blast! that was the home of Warren Ellis' first creator owned strip with the artist D'Isreali called Lazarus Churchyard. Edited the first Heavy Metal special for its new owner Kevin Eastman. Monster Massacre, Ammo Armageddon, Carnosaur Carnage, Penthouse Comix, Men's Adventure Comix, co-founded Radical Publishing/studios, etc.
And now I have come full circle and back on Heavy Metal specials and preparing for the relaunch of A1. But this time I'm back as a creator.
Btw: not official yet, but who reads my page anyway, A1 will be launched first on deviantART in October and won't be available in print until 2013, but you will be able to pre-order through me with exclusive covers. We'll also be offering a Malaysian language edition at the same time.
And here are a couple of very good columns written by Mark Waid on the subject. Mark started as an editor before moving into writing and often wears both hats, though not always at the same time. I've avoiding going into too much detail as Mark's already done it, but every editor will have different perspectives based on their different experiences.