What is the best comic page dimensions (in both pixels and inches) for this site?
Vertical is no issue, as scrolling down is easy and common, but I'd like the width to all be seen without having to scroll left.

Any help is greatly appreciated, thanks :)

For width many people post at 640 pixels wide.

I do mine at 800 wide.

Thanks :)
I went with 900, it seems to work pretty good.

I work in 3000x5000 pixels (10in x 15in, 300dpi), and reduce to 800 width keeping the vertical ratio. Works pretty well.

I usually post at 480 pixels wide, mostly to keep the file size down and the site speed up ;)

If you're asking about paper size, go with whatever you're comfortable using, though the most common thing to do is to draw it bigger than it would be printing, since, to a degree, the reduction in size will make the images sharper.