How do i add a new domain?

See Installing Multiple Blogs and Installing WordPress.

[moderated – link fixed]

The first link, which is the one i am looking for, does not open.

I would really appreciate if you could help me out here. Thanks.

ruanz3 – remember if you are ever stuck like that, that a search like this:
https://www.google.com/search?q=wordpress+multiple+blogs

will return interesting results.