Ghosts are usually distributed in NAR files. These are basically zip files, but specially made and associated with the SSP program. Luckily for you, making a NAR file is as easy as pie.
First, clear out your ghost's folders of any psd or extra files you might have been using while working on it, since those'll add to its NAR size. You can just put them in a work folder or something, since you might need them later. Run your ghost, and open up a Windows explorer window for your SSP/ghost directory. You should see all the folders for all the ghosts you've downloaded, including the one for YOUR ghost. Drag and drop your ghost's folder on top of your ghost.
When you do this, a text box will come up that is completely in Japanese. SSP updated enough so that it is now in English! Which makes things much easier.
The first option will make a new update file. This is for those who set up Network Update in the previous phase. If you didn't do this, ignore this option.
The second option just makes a NAR file.
The third option will create both a NAR file and an update file.
The next two I'm not quite sure on. Make Zip+txt update package is a brand new feature that I haven't really experimented with yet, and I'm actually not sure what Ignore D&D and Report to Ghost does, honestly.
Click the second or third option, it's your choice really. The ghost will tell you it's making a NAR file, and it will ask you where you want to save it. If you chose the third option, it will do the same for your updates2.dau file. You now have the NAR file for your ghost! All you have to do is upload your .nar somewhere, link people to it, and you're done!
Before you completely let it go, you may want to make sure your NAR file actually works. To do this, you can install another copy of SSP in another folder on your computer then run it. When the default ghost pops up, drag and drop your new NAR on top of it. It should install your ghost. Swap over to it and check that it works alright and is behaving properly! Hurray, you tested this and made sure it worked before you linked to it anywhere!
You could also enlist a friend's help by getting them to install SSP and then use your NAR to install your ghost. If it works for them, then it should work for everyone!
Now, if you made a balloon with your ghost, you're going to want to zip it up separately. Your balloon may actually be included when you make a NAR but I'm not entirely sure. Either way, why not be thorough, right? Maybe someone will just want your balloon.
Anyway, to do this, just go into the SSP/balloon directory, and zip up the directory for your balloon using Winzip or 7-zip or whatever program you got. Name the zip whatever you want, and link to it along with your NAR file. You can test this just like your NAR by dragging and dropping it on a fresh ghost to install it.
On the Network Update page, I talked briefly about setting up a tiny page for your ghost to serve as a hub. It's actually pretty convenient to have a solid, non-changing place where people can find your ghost or information on it, but a lot of people nowadays don't want to make personal sites or don't know how to, so that's okay. What you can do instead is just make a solid entry for it somewhere. Make a post on your blog or whatever for your ghost. Put all the information a user would need on there - how to download it, how to install it, how to install SSP, how it works, any information you think would be useful.
If you're going to update your ghost in the future but aren't going to use the Network Update option, a solid post like this is even more useful. You can write down in the post when you updated and what you updated, and link to the new up-to-date NAR file you made.
If you have stipulations about your ghost, like how it can be distributed by others or how you want to be credited or linked back if people post caps or something like that idk, put it on your post for it. You should also put information like that in your readme. I'm not really sure what stipulations people would have for a ghost - who knows? But it may come up.
There is a big hub site where people share links to their ghosts, but the site is entirely in Japanese. It's called GHOST TOWN. If English ghosts ever take off (please please), perhaps some kind of hub like this will get set up where people can trade and advertise for their ghosts. Right now, I don't think any such thing exists since at the time of writing this there are like three Ghosts in English and one is the template you've been using and another one was taken down by the creator (the last one is Hunter and Smoker). But feel free to advertise your ghost as many places as you want to try and drum up interest! Ghosts are admittedly a weird little pointless doodad, but if you've come this far, god knows you've spent enough time making one. Who could fault you for wanting people to see it, right?
There is an equivalent to GHOST TOWN called BALLOON TOWN incidentally, which only focuses on balloons and is also in Japanese. It's fun to look around at all the balloons people have made, and you might get some inspiration for balloons you might want to make yourself. Another place where Ghost news is posted is Disc-2, another Japanese site. Usually they'll make posts for new ghosts or balloons people make which can be fun to check out. Of course, they are almost all in Japanese, but that doesn't actually affect very much for a balloon, haha.
I mentioned this before in the very early stages of Ghost creation, but I will say it one more time for the record. Try and give your ghost's folder a unique name! When you dragged and dropped your NAR onto your ghost, it installed your ghost to the folder specified in your install.txt file. If that folder ALREADY EXISTS but for a different ghost, then bad things will happen. It's POSSIBLE SSP will ask if you want to overwrite it, but it may just straight up do it without asking. I've seen people complaining about this on Japanese sites, thus why I'm being clear about this. So just try to be unique. It can be as easy as putting some of your initials in front of your ghost folder. Since English ghosts are so rare right now, it seems unlikely that ghost directories are going to overlap very much, but who knows.
I can't actually think of much more to add to this section. If you've come this far, you are done! You made it! You finished your ghost! You should feel very proud. If you found this site or my template helpful, I hope you'll link back to it so others can use it, and let me know about your ghost so I can see it! I really am endlessly fascinated by these things, as if this enormous walkthrough wasn't enough of an indicator.