Okay so for that, what I've done in the past and what I suggest is to not just do a typical four-page signature and fold in half and staple, because the paper is going to be very fat for such a short and little comic, and you're going to wind up with some very significant staggering on the flip-edge of the mini comic that is just not very pretty.
When I've done a similar size and length of a mini comic, this is how I've done it. It's a little time-consuming, but it's always turned out really nice.
In Photoshop, I'll create a printing and cutting template. You need two versions, one for "front" pages and one for "back" pages, because the binding border will be on the opposite side for right versus left pages.
So the red is where the actual art would print, and the blue is where I would cut. I cut just inside the blue lines so it's not visible on the final product. As long as you have your templates centered vertically and horizontally on your page and make sure you're aligning your paper properly when you feed it into the printer, everything will line up evenly front-to-back. You just need to make sure you do every other page on the "back" template.
For paper, I suggest using 32lbs printer paper for the interior, it's a little bit nicer than the typical 24-26lbs printer paper, but still thin and flexible enough that it won't be difficult to flip through pages. Then use a light card stock for the front and back cover, like a 80-100lbs paper.
You can absolutely print this yourself at home if you want to, I always do my own. If you have a laser printer, the colors will look a lot better than ink jet, but either one will work. Or you can totally get things like this printed at Staples or FedEx Office or whatever, though I suggest doing at least a test print at home before you send it out to make sure you've got everything in order properly.
Once you print it out, just cut out each of the pages using an exacto knife and a ruler. Stack everything up evenly, and use a binder clip to hold them together tightly. Don't put the binder clip directly onto your pages though, put a folded paper towel or a bit of felt between the binder clip and your comic pages so you don't wind up with an ugly indent on your first and last pages.
Once everything is lined up and attached securely, use an awl to stab holes in the marks on the printed template. Then you can use a waxed thread to do a simple Japanese binding on the spine.
After you've finished binding, you can remove the binder clip and you'll be good to go!
That's the technique I use for most of my mini comics that aren't just the standard 9-fold minis. That picture is a different size, but it's about 2.5" tall and is 32 pages and is waaayyy nicer with this style of binding than a very similar one I did that was fewer pages but I just did a fold-and-staple printing and binding. The fold-and-staple one just felt chunky and it didn't stay closed nicely because it was too many pages in a too-small format, and the edges were staggered unpleasantly because of the thickness of the final product.
