enable places you in admin/root mode
Notice that the prompt changes to reflect the level you are in, in this case from Router# to Router (config)#
Notice that the prompt changes from > to # just like in Linux
configure terminal or conf t places you in configuration mode
The hostname command allows you to name your device
The enable secret command allows you to place an encrypted password on the enable command
Banner motd $ message $ allows you to create a Message of the Day for all people logging into the device