This post is no substitute for the considerable support materials available. In particular, Steve's help and FAQ have good material on setting up a new web site. Moving from one hosting service to another is a special case of setting up a new site. This post concentrates on things that actually caused me some trouble, and adds a few things I thought of on my own that might be helpful to a fellow neophyte. Any pro who wishes to correct or extend my remarks would earn my gratitude.
CHOOSING A HOSTING SERVICE
One could spend a lifetime on this one. I briefly looked in to the services suggested in this thread on this site
hosting thread, then decided just to go with the A2 Hosting bottom end offering, accepting the 3-year prepayment condition to get the cost down a little below $50/year, though renewal after three years is promised to be twice as expensive. You can doubtless get good service for less.
I was surprised at how small my file footprint on the server to support (standard, not MX) Cumulus proved to be. 68 files totalled under one Megabyte. The traffic is not so tiny, however. I update on a 5 minute interval, and consume about 5 Gigabytes/month of uplink traffic from my PC to the server. I am very confident that my viewers consume very, very much less.
HOSTING SERVICE INITIAL INTERACTIONS
During signup A2 hosting wanted to know what domain I'd be using and how I'd come by it. I selected the option for "I already own a domain, and I want to redirect it to point to you, and I don't want to give you management of the domain".
A2 Hosting sent me an e-mail within moments of accepting my payment, with details in the email or at the click of a link for the crucial things I needed. Chief among these were a URL which would point at my new site even while my domain was not yet retargeted, FTP transfer credentials, and the name servers necessary to use to get my domain to point to my hew hosting site.
MOVING MY STUFF FROM STEVE'S HOST TO THE NEW ONE
My first stumbling block here was that my long-time FTP application, FireFTP, appears to have not made it to modern editions of Mozilla FireFox. This was worse than it sounded, as I'd lazily relied on FireFTP to remember my credentials. I chose FileZilla for FTP. I found that the configuration file Cumulus.ini on my PC had my credentials in the first five lines of the FTP Site section.
With that taken care of, I created a directory on my PC (Backups), and selected it in the left pane of FileZilla, and selected the top directory of the weather containing stuff on Steve's server, right clicked and selected download.
It was slightly trickier to get the FTP credentials into Filezilla to move stuff to the right place on my new A2 hosting site. The A2 hosting message did not quite use the same terminology. The only port they mentioned was the SSH port, but that is wrong for FileZilla FTP use. Filezilla worked with Port 21, as is usual for FTP. The really sticky point was what Steve calls "directory". I had to wander around the A2 hosting documentation a while before bumping into a mention that only files and directories under the (pre-existing) directory called public_html would be accessible to visitors on their web browsers. I guessed that this meant I should arrange the material I was moving from Steve's server to A2 so that public_html occupied the position that www occupied at Steve. This was true.
My test process was to copy the full Cumulus site tree onto the new server, then use the "no domain move required" URL A2 provided to check that I could actually see my saved Cumulus web pages (complete with unchanging, and thus out-of-date last update notations).
POINTING MY DOMAIN TO THE NEW PLACE
My domain (pastoll.info) I rent for a year at a time from my domain registrar, which happens to be Google's domain service. Other registrars organize their user interface differently, but some common issues may apply. When logged in to the Google domain service I needed to get to the section on DNS issues. The only thing I needed to do there was to indicate that I'd be specifying nameservers, not using the Google defaults, and actually entering the four nameservers that A2 supplied. It was also crucial that I click the "Save" button. That got me an alarming highlighted warning message that in departing from the Google nameserver standard, I was losing other Google-controlled stuff on that page. That turned out to be what I wanted.
My stumbling block on this page was that I expected to need to supply an actual address (either IP or text string) for my new server location. I had needed to do so to use the immediate previous Steve server, but that one had me using default nameservers. With specification of A2 hosting nameservers, Google was uninterested in any kind of address. (good thing, as the field would not take a text one, A2 had not supplied a numeric one, and I did not trust that the numeric one I discovered by ping would be stable over time).
WAITING FOR PROPAGATION
All standard instructions tell you to expect a significant delay (up to a day) before a change to the place your domain points to takes effect (it literally propagates round the world, I guess). I monitored this process by keeping open a command line window, and doing a new ping to my domain about every five minutes
ping -n 1 pastoll.info
I also had open a browser window to a page of my weather site, using my domain address. As I had not updated the FTP section of Cumulus yet, the site getting updates was the old one. So when I refreshed the browser window every five minutes, if the page updated time at lower right was fresh, my browser was still getting data from the old place. Having saved the nameserver change at 7:01 a.m., I saw both methods indicating it had taken effect a little before 7:56 a.m.
POINTING CUMULUS TO UPDATE THE NEW PLACE
With my domain addressing updated, any user looking at my site was now seeing stale data, so it was time to update the Internet configuration page for Cumulus, and I hit my last stumbling block. I knew perfectly well that I needed to type "public_html" into the directory window, but at the moment of typing my brain faded and I instead typed public_ftp. On hitting update, I got normal looking progress indications from Cumulus (pop-up box, announcement of logging in to the new host, changing directory, and sending various types of files). Nothing useful accomplished, however. Once I fixed the faulty entry in the Cumulus Sites/Options|Web Site section, hitting the web update item gave very similar popup window messages, but this time the web site I saw in my browser was updated.
TOUCHUP
A2 had pre-positioned an index.php file, which seems the way they have things configured to have taken precedence over my Steve-related index.htm file. Fortunately they populated it with text suggesting that a new owner would want to delete it, which I did.
ALL DONE BUT THE CLEANUP, AND MY NON-CUMULUS PROBLEM
I've not yet removed any files from Steve's server, and plan not to for a few days, just in case... My remaining problem is that some non weather related files I've moved onto the new server don't show up to a browser the way they did on Steve's. I suspect this is some site configuration option, possibly related to the lack of an index.* file in the directories of interest. But I need to find a way around it, but maybe not today.