Sounds like sshd isn't running on the machine you want to connect to. I assume it's like in Mac OS 10.1.
sshd should be in /usr/sbin/
If this is a new installation, you may have to generate ssh keys prior to starting sshd. Here's an excerpt from the INSTALL file for openssh:
------------------
To generate a host key, run "make host-key". Alternately you can do so
manually using the following commands:
ssh-keygen -t rsa1 -f /etc/ssh/ssh_host_key -N ""
ssh-keygen -t rsa -f /etc/ssh/ssh_host_rsa_key -N ""
ssh-keygen -t dsa -f /etc/ssh/ssh_host_dsa_key -N ""
------------------
In Mac OS 10.1 the keys should be in /etc/ rather than /etc/ssh/
Assuming you have root privileges or can sudo, you can just generate these keys (don't do it if they're already there) and then just start sshd. When that's done, you should be able to log into that server using ssh from another machine.
/stone