how does I get web-site hosting?

If I buy a domain name from some registrar, what then will I have to do in order to host a web site (or any other server) on it?

I know of web hosting services.  What is a good one with unlimited bandwidth?

Also what is a reputable registrar?  I've heard recently GoDaddy and NIS have been shitheaded in their behavior.

Never buy from a registrar, always buy directly from the NIC.  Become a registrar if you have to.

I know of servers. What is a good one with unlimited RAM?