how to block bots from certain domains accessing my website

[toktosunov]

in recent days, according to my web logs, bots from a particular domain - subdomain1.domain.com, subdomain2.domain.com etc., have downloaded nearly 500 mb of my content wasting my bandwidth and stealing my content.
how can i prevent agents/bots coming from this domain or ip from accessing my website?

[jomaxx]

Look up how to use the .htaccess file (for Linux systems). You can ban spiders by the name that appears in your log or by IP address.

[toktosunov]

so can i do it?
I looked up .htaccess and there is a lot of information. All i need is to block bots from a particular domain.
i am not a technical person, i would appreciate if someone could show how to do this.