If it's a new doamin, you can connect to machine.dreamhost.com to transfer your files. You should have gotten instructions on how to do that with your welcome E-mail.
Also, would you be, by chance, behind a firewall that might be stopping you from connectiong?
A 'ping' is a basic way of checking the communication lines between your computer and some server. It's a useful way to see if there's issues with connection the to server, or if it's in your settings. To ping a server, from windows, click Start > Programs > Accessories > MS DOS Box. A little black box should pop up, and give you a place to type. This is a command line. From here you can type:
And you should get some information back. Your computer will ping the server three times, and report back to you if each ping was successful and how long it took. Now trying pinging your domain name - whatever.com and see if that works. That's how a ping works.
You're also more than welcome to keep posting in this forum. There's more likely to be more people to help you out here, rather than E-mailing someone.
Hope this helps