In a development environment, your server will be called localhost and you will trick Windows into using any domain name you want. But if you post on the Internet, you will need a real domain name. All the good names seem to be used up, but with some patience, you can find one that will work. I use my Hosting provider’s Domain name search (Web Hosting Canada) to see what is available. You can use other reputable search sites like WHOIS. I say reputable because there is a slight chance an unreputable site might scoop your Domain name on you as you search. It is always easier to register your domain name with your Hosting Provider rather than using another provider and then having to point the domain to your hosting provider’s name servers. If you are going to set up domain email addresses (which I recommend) having one provider makes it easier. Keep all your transactions in one place if you can. Try to use a .com site unless your site is specifically targeted at a specific country or classification.
If you are just posting public information and aren’t asking for user input, HTTP is fine.