Okay, this article addresses the issue of getting paying work, the holy grail of the comic artist. Until you get picked up, hopefully, by a publisher, this should allow you to avoid some of the pitfalls of the aspiring artist.
First of all, you respond to ads on sites like Digital Webbing, Penciljack, Deviantart, or, COMIC RELATED. If you are lucky enough to be selected-because for every paying gig there will be at least a hundred applicants-here is how you should handle it.
Many artists have unfortunately experienced being 'hired' to do a book, with payment upon completion, and they never get paid. So they basically drew 22 pages for someone, for free. A good policy is to ask for payment every 5 pages. Anyone not willing to accept these terms will probably screw you anyway, so no loss. Another strategy is to send the pages at 72 dpi until you get paid - that will make the pages worthless to any miscreant trying to cheat you. You can also use strips of paper to block off parts of the pages so the writer doesn't have complete artwork until payment arrives.
Another thing is to be flexible. If the writer wants changes, be happy to supply them. Never argue that what you drew was correct, and the writer is simply wrong. Hey, he's paying you, and this will give you experience for the big leagues, where changes are expected to be no problem. Of course, if you run across someone who wants too many changes, over and over, well, it may be best to part ways. Make your own decision on this. You definitely do not want to get a reputation for being difficult and unwilling to accept critiques of your work.
You will probably experience writers who ask you to draw the impossible, like a back view of a guy with an angry expression on his face, or a long distance view of someone with a detailed facial expression. At long distances, eyes are just dots. Or someone may script you drawing someone showing their thoughts, eg 'John enters the room. he is thinking about Marie, and the difficult way they parted.' Now how the hell are you going to draw that? So a good rapport with the writer is essential when you have to explain why something is undrawable, and you can offer alternate suggestions for the panel in question.
Also, writers sometimes script several actions in one panel. EG 'John enters the room, walks over to his desk and opens the drawer to see a rat inside!' Okay, there are 3 seperate actions here. ONE PANEL, ONE ACTION! Break it to the writer gently. Also be on the lookout for writers who script without using any of the characters' names. This is actually fairly common. It will be up to you to remind him or her that the reader will not have a script showing who is talking, so it is up to the dialogue to provide this info. Most writers will appreciate this input.
How much should you get paid? Most amateur level work for pencils and inks is $20-$30 per page. When applying for jobs make sure you send LINKS to SEQUENTIAL ART. No pin-ups! Nobody wants to see pin-ups and they are a sure sign of an amateur not ready for prime time! Also, if you are a non-American artist, it is critical that you are fluent in English. No matter how good you are, the language barrier will be too much to overcome. It's hard enough grasping panel descriptions as it is sometimes! And don't try to trick a potential employer about your language status!
Production: if someone is paying you to draw, you should be motivated enough to produce at a bare minimum two pages per week. Four is better. I do seven myself. If you can't produce a measly two pages per week you are not ready for paying work yet. This is critical-DO NOT BECOME EMOTIONALLY ATTACHED TO YOUR WORK. People are going to be saying things like 'the guy in panel two-his face looks off somehow-goofy' or 'the perspective is weird in panel 5.' This should not upset you at all; in fact, you should WELCOME and ENCOURAGE criticisms-that's how you learn-and learning is how you get better-and getting better is how you break in with MARVEL or DC or DARK HORSE. A lot of artists get upset and their heart starts beating really fast when someone criticizes their work. This is a BUSINESS, pal, leave the emotions at home with your wife.
When sending your pages, use 300-600 dpi jpegs if that's okay, and it usually is. Tiffs are for big time publishers where your work will end up being colored, never for webcomics. And dont forget to leave room for the word balloons at the top! Find some system that works for you!
Ok I hope this helped!