THIS EDIT IS IN PROGRESS - STILL NEEDS IMAGES AND ADDITIONAL TEXT
For more information on covers, please see the Covers FAQ.
An Illustrated OI Tutorial
Log into the system on the front page by using the username/email and password you created your account. If you have problems logging in, check if you've got the caps lock on - it may affect the login procedure. Fill in the two fields and click "Login".
You should have cookies turned on in your browser. If the first thing that comes to mind is Oreos, you've probably got them on already...
Adding Covers Step-by-step
1. Choose an issue to add a cover to Search at the website http://www.comics.org for the comic you want to submit a cover for. Each series has a section called "Cover Status". If the cover you want to submit isn't on the website, the Cover Status should show that issue as white. If you want to replace an existing cover, please see Replacing Covers Step-by-step below. If you want to add an additional cover to an issue that currently has a cover, see Adding Additional Covers Step-by-step below.
2. Click the number of the issue You will be taken to a page asking for the name of the file to upload. Click the "Browse" button to find the cover on your local computer.
3. Source If you have gotten the cover from an external source (please ask if this is OK) mention it in 'Source'.
4. Remember the source
5. Mark cover for replacement If you believe the cover is in poor condition and does not meet the standards listed on the upload page, tick the mark (such as in case of a bad scan for a rare comic).
6. Wraparound cover If the cover is a single image that wraps around to both sides of the comic, tick the mark.
7. Gatefold cover If the cover is a gatefold cover, folded into the comic, tick the mark.
Per a vote of 2010-11-11, when a gatefold or wraparound cover exists for a publication, only the full version of that cover is considered a proper or 'best' cover image. If the contribution of a full gatefold or wraparound cover is not possible due to technical limitations on the contributor's end, the contributor MUST  note in the Comments field that only the front portion of an extended cover is being uploaded and  mark the cover for replacement. Gatefold or wraparound covers that are currently in the database in miniature, as well as front-only portions of such covers, should be marked for replacement by users when noticed. This policy only applies to publications ONLY with sequences (most commonly illustrations) that span front and back portions of a cover, including fold-out portions in the case of gatefold covers -- NOT to publications with discrete content on what are commonly separated as front and back covers.
8. Comments Add any information you wish to communicate to the editor. Examples are details about the source or condition, or questions you want to ask the editor.
9. Upload When you have all the information ready, click the "Upload" button.
If for some reason you can't submit covers through this page, feel free to contact the editors via the Error Tracker at http://errors.comics.org . Covers can be attached to the error report after it is submitted or, alternatively, one of the editors could contact you with an email address that the cover can be sent to.
Adding Additional Covers Step-by-step
Variant covers can be submitted via the 'Edit cover' link present on the issue page, the 'Edit covers' link on the large cover view, and the 'Add/replace cover' link under each cover on a series cover gallery page.
For adding a flip cover, you simply hit the "Add additional cover (dust jacket, flip cover)" button from the "Edit Covers" page you find at the bottom of a cover view page.
Moving Covers Step-by-step
For moving a cover from one issue to another use the "Edit with another issue" button instead of the "Edit" button. On the following page one can select/find the issue to/from which the cover should be moved. The selection works by searching for an issue, or choosing the issue which was 'remembered' before, or entering the issue ID (the final digits in the URL of an issue, for example from http://www.comics.org/issue/154638/ you will need "154638"). Besides moving covers by pressing the button "Move covers between both issues", you can make other changes to the issues before submitting as usual, if desired.