If you are really wanting just to do the vanity press thing, check out someplace like Ka-Blam that will print very small runs (even a single book.)
They have templates you can download and all the information you need to know. I've been looking at Ka-Blam lately for a graphic novel that I just want samples of so I know they have downloadable templates that have the live/trim/bleed areas marked out. They print strictly from 300dpi tiff files.
It's smart to consider all of these things *before* you start.
Since what I'm doing started as comic strips and I'm reformatting them into comic book pages, I've had to consider things like type size. Obviously, it needs to be large enough to read on screen at the size you display it, but large lettering looks odd in modern day printed comics, where sometimes the lettering gets *really* small. I do all of my lettering in Illustrator, so it wasn't difficult to change this when I reformatted, but if you do it in Photoshop, make sure you keep layered files so that you can adjust when the time comes to print. Or you can try to find a happy medium that is big enough to read on screen, but doesn't look giant on the printed page.
In my case, this was a plus, because the benefit of reformatting the pages into comic book pages was allowing for more of the art to be seen. Increasing the size of the art and decreasing the size of the lettering and balloons really made a difference in that regard.