Noob trying to SSH (Help needed)

Anyone mind helping a n00b?

I just set up my RPi (with the piratebox image, wifi, and external HD attached)...

I'm trying to SSH into it for the first time using the instructions on the website, but my terminal keeps telling me "ssh: Could not resolve hostname alarmpi: nodename nor servname provided, or not known" when I try to use the 'ssh root@alarmpi ' ... Any obvious reasons why this isn't working?

Am I supposed to have gotten/created an IP somewhere? (The instructions on the website don't mention anything about it.)

Could the external hard drive I've got connected kept it from even getting to the point of accessing the RPi?

All help appreciated.