So you've written a comic book and now you want to publish it. The next step is convincing a publisher to take a risk on you. Here are a few tips to get you on their good graces.
Give them exactly what they ask for. Every publisher has a slightly different request in terms of submissions. Some want a cover letter, some don't. Some will ask you for character profiles while others expect that to be covered in the plot synopsis. Some will ask you for five pages of script. Some want the whole thing. Whatever it is they ask for, give it to them. Some writers believe their work is so incredible; it will stand on its own. Without some stupid plot synopsis or cover letter. You may hate writing these things, but the editor wouldn't ask for it if he didn't want it. Some writers find it helpful to have someone close to them write some of these materials. If you aren't good at marketing yourself, you might consider getting that kind of help.
Step2
Don't be afraid to put a little extra effort in your packet. If they want a 3 to 5 page plot synopsis, make it 5. If they want 5 to 10 pages of script, give them 10. Include any optional materials possible. This includes any artwork you might have. If you have sequential pages, letter them. These people read comic books for a living. If you can show them that the assembled comic will work in the end, you'll be that much closer.
Step3
Double-check all of your materials for typos. If your submission is full of mistakes and errors, they will take that as a sign of your standard work ethic. You don't need any special folders or bindings, but make sure your packet is professional looking.
Tips & Warnings
Try to think outside the box. If you can add something unusual that will catch an editor's attention, they will continue to think of you.
Don't leave the ending out of your plot synopsis. This is vital information that an editor will need in order to make a decision. Be clear and specific.
Enthusiast 
