Scrolling Along

Pick up a newspaper or a book. When you reach the end of a line, you move down to the next one. When text you're reading gets too low, you shift the book upward. Notice how you don't shift the book side to side except when moving on to the next page/section. Up-down scrolling is natural, left-right scrolling isn't. The width & height of a comic should reflect that. See that space at the bottom of the screen? where the horizontal scroll bar goes? Make sure that stays empty.

While a computer may be set at higher resolutions, normally it's at around 1024x768. 800x600 is still pretty common, so it wouldn't hurt making 800-pixel width your upper limit. By all means work in a higher resolution if you wish, just make sure to resize it ahead of time using a real graphics program; relying on the browser to do so via the IMG tag's size attributes is detrimental to the quality. Using those attributes also opens the way to comically stretched and distorted images.

As long as I'm on the subject of scrolling, the ideal situation is no scrolling at all. That means comic is in the first screen-height of the page, the major links are there, the major news posts are there. Think back to all those English courses, the most important parts should be right up front.

Be nice to your readers. Spare them a little pain viewing the comic, and you've started accumulating brownie points.