The samisite.com forum is stored and run from the samisite.com web space and so is the database.
I maintain the forum using update packages from a browser screen inside the ADMIN panel.
I can turn on and off different options, limitations, etc.
Nothing is built/maintained on my own computer. I do keep a backup of all the forum files on my pc.
There are MODS you can add or themes you can load to expand capabilities.
But each MOD may not be compatible with the next update package. (found that out early on)
With each post, the database grows and takes up more of my web space.
I disallow attachments to limit the amount of space used for the forum.
SMF and other forums are a package you download to your computer.
If your control panel (like cPanel) can "unpack" (like unzip) you upload the package to the hosted space and extract it.
If you can not unpack on the server, you do it at your own computer then upload the parts to web host.
Put package or contents into the folder where you want the forum.
Using the FULL install package:
In the browser, you go to the install.php file in the forum folder.
It walks you through the setup, tying to the database, etc.
You will be requested to provide answers like where are the databases stored, etc.
So you need info from the host before getting started.
The installer can set up database for you if you provide permission.
But you might want to take a look at the WEBINSTALL instructions. The latest (they say easiest) way to install SMF forum:
http://wiki.simplemachines.org/smf/WebinstallCan download it here:
http://download.simplemachines.org/ (scroll past full and upgrade to get webinstall)
It stops and starts during download to limit drag on server.
When done extracting, it will send you to the proper installation page to answer questions to set up the forum.
(Note that when I upgraded to v2 from 1.1.14 the webinstall did not work for me...
so I came up with another way!)