If you are going with a commercial host you shouldn't need anything, except Nuke and whatever you want to add to it later on.

You can leave the folder named html or not. If you want Nuke to be in your domain so that when someone puts in www.yourdomain.com they go directly to your Nuke index page, then you upload the contents of the html folder (maintaining the directory structure). Otherwise you will have to redirect or put some kind of index page up there seperately, because your nuke index will actually be www.yourdomain.com/html/index.php

Does that make sense?

If you are installing for the first time. Get Nuke 6.5 it comes with forums etc. After you install it and you know it is working, then install secfix 3 and 4 available at Nukecops Delete modules/webmail/attachmail.php (just that file) it leaves a security hole even if you attachments set to no.

Then poke around with Nuke and see what it can do for you.

Just make sure if you decide to add any mods, themes etc that you get ones that will work with 6.5 and if you are adding things to your forums, you need to make the same modifications to each theme, or else your members wont have the same features on each theme.

Nuke comes standard with a bunch of themes, you don't have to use those ones. You can get packs here they are easy to install. Just maintain the dir structure when you are uploading. After you have a default theme that you like, you can delete the other ones off your server. Make sure that you have set that theme to your default theme in admin/preferences otherwise you could run into problems.

Happy nuking