Let me replay what I think you want to do to make sure I understand it right:
You want to buy domain names, all of them will just have a for sale sign for that domain name. Your plan is to resell the name and make a profit.
So, here is an overview (hope it will help you how where to start):
Part 1, the name
First is the domain name registry. If the name you want is an available name, you buy the names from a domain registrar. Most domain registrar also offers name services and hosting services.
Once you got the name, you can now specify where (what IP) that name goes to. So, you use your domain registrar's DNS service to enter an IP that you own/control into their name server. You can have ALL your domains pointing to the same IP (same server).
You can run your own DNS server too, but that is beyond the scope of this overview.
For example:
Since I own domain ricklaw.us, I can have many servers with that single domain name. A server I choose to name "secret" can go in my domain as secret.ricklaw.us. I can have another server electronics.ricklaw.us. Each server needs an entry in my DNS – which is actually me creating an entry in my registrar's DNS server for the name(s) I own. The names secret.ricklaw.us just points to a server by IP. It doesn't mean it is a particular type of server. It could be a mail server, an FTP server, whatever.
Note of course common nomenclature. For example, www for world wide web server) and mx for mail exchange server, so on.
So, with your name in the "global phone book" (ie: DNS servers), a user from the outside can get to your server using that "phone book". He (the application) asks the DNS of the world and eventually the request gets to your registrar's DNS server which will return the IP you entered for that server.
Part 2, the server
Now the user have an IP, it knows how to get to your machine, it could be a web server or whatever type of server. In your case, you have a simple web page server.
There are plenty of web server hosting services out there. Your domain registrar probably have web server hosting service also. You need only one server. All the domains you own can point to that one server. (ie: all the entries in the DNS have the same)
You can make up that simple html "for sale" page, or use whatever tool your registrar's server has and make something fancy. Google hosts webpage also, but in the way they configure it (or used to configure it), you will probably need to replicate the page(s) into each domain name google hosts. I have not used Google web host for a while, so I am not sure how they are like now.
Different companies have different mix of services, here are two you need to look into. They may call it something else but typically:
Server hosting - host your hardware in their shop, or rent you a machine/virtual-machine.
Web hosting - you don't have your own machine, but you have your own website on a machine that may house web servers for other clients.
I personally use dnsexit.com as my registrar/host. They also have server and web hosting. Since your flag is Canada, I think godaddy.com is a Canadian firm (not sure, just think so). They will host your domain name and have server hosting as well - or at least they used to. As I said earlier, there are many registrar/hosting firms out there. Search the web for one that will give you the best deal.
Part 3, the machine at home
You can use an old XP machine and it can serve simple pages. But you will have reliability problem. For consistent service, you will also need a fixed IP. You can get by with "dynamic IP". Typical consumer internet connection have "dynamic IP" which means it may change by itself at intervals selected by your ISP.
Some DNS services are dynamic. The one I use dnsexit.com has dynamic DNS capability. I run something that keep detecting my IP and connect to them to update when it changes - which means there is an exposure. How frequent do I run my IP update, what if the customer happen to look between ISP's IP change and my IP update application actually updating.
Then there is power outage, etc. You said you want to do it right, so I suggest best is having a professional hosting service host it.
This is a quick overview, I hope it helps.
Rick