The second level domain to a home server

dyndns
buy a domain and put on the machine a program which will always keep the ip current

Peterhost for 30p / year offers.
\r
In order to have your domain (without delegation), it is enough to just buy from any Registrar in the area .EN. Well, every year\\or two to renew the registration by paying the Bank notes.
\r
To the house to standing in the corner of the server (assuming the external IP is fixed) to attach this domain, it is necessary to configure DNS. For each domain must meet two dns servers, primary and secondary, located, preferably, on different networks. One thing you can configure on your server in the corner, something the second — on the server of the other. Any of these servers can provide as a service, and the Registrar. For example, the same nic.ru sell you the domain and offering a service Primary DNS with a web muzzle to edit a zone (i.e., setting the domain and subdomains) and Secondary DNS. Each of the services, afaik, is at 150r / year.
Thus, as one of the options — regalim domain, the ordered secondary dns, primary dns picks up the house and quietly rule your domain from the comfort of home server console...

buy domain (nic.ru), Park somewhere( Google domain Parking ), and enjoy life ))

here
p.s their customers in almost all routers

To buy a domain, then buy DNS hosting.
I for such purposes use peterhost.ru
(the zone of the domain is prescribed ns1.peterhost.ru, ns2.peterhost.ru)
Fee of 30 rubles per year, you can register up to a hundred domains.
Will need a dedicated (fixed) IP from your ISP, it costs about 100-140 rubble per month.

free to domain in the area of tk, but I do not advise. as soon as a lot of visitors, they will take your domain and hang a doorway.
\r
you can buy cheap and honest domain for example, 2domains.ru. reviews they have a good (Google for habru)

Which zone domain name?
If .EN — will fit any of the accredited registrars. For a domain to "earned", will need to set primary and secondary DNS servers that will host the zone. There are free DNS services.