1) # su - (to login as root)
2) # cd /etc/init.d
3) # nmap localhost (to see what all services are running)
4) # service sshd start (to start the ssh service)
5) # nmap localhost (again run nmap to see if ssh has started running)
You can start any services using the "service start" command. 'start' can be replaced with 'stop', 'status', 'restart' to see respective results.