I have a registered domain and i need to use my own server to host my website, I have understood the risks of hosting my own site but anyways want to pursue this , so how to bind our registered domain to our own host server?
You can use host your DNS on a website such as Afraid.org and set it to point to your home IP.
To do this, make an account on Afraid, go to your registrar and set your nameservers to the ones mentioned on Afraid.
Then, on Afraid, add a new A entry for your domain/subdomain to make it point to your IP address (or CNAME entry if you want to point to a different hostname).
If you've had experiences with other free DNS hosting services please share, I only tried Afraid and I didn't feel a need to use a different one.
It will be significantly less stressful to use a VPS from DigitalOcean, Linode or Amazon. A $5/month "droplet" is a good place to start. There are a ton of guides out there on setting up the web server, then you need to make DNS changes to point www.yourdomain.com to that web server.
It's too big of a question to get into how to setup the web server, or make the DNS changes. If you start going and have issues, come back and search in superuser, unix or askubuntu on stackexchange. Whatever questions you have, they've been asked before ;-)