This How To explains username configuration. Short and sweet.
Step 1: With use of below command we can create User in Cisco Router
Cell_Router(config)#username AWALDING priv 15 password CELLSTREAM
Step 2: Also, we have to enable this at each line
Cell_Router(config)# line con 0
Cell_Router(config-line)#login local
Cell_Router(config)# line vty 0 15
Cell_Router(config-line)#login local
Cell_Router(config)# line aux 0
Cell_Router(config-line)#login local