adding navigation items to my horizontal menu bar

I would like to add an additional menu item to my horizontal navigation bar. I have read this page http://codex.wordpress.org/Creating_Horizontal_Menus

but still don’t quite understand. i attempted to add the coding once before and it created an error (obviously i put it in the wrong place or something) and i was unable to access my site until someone from my host site (blue host) undid it all for me.

Is there anyone that can give me (a NOVICE) very straight forward to directions on how to add “the poem” as a menu item next to “home” on my horizontal menu bar. my site is filamentagainstthefirmament.com for reference. THANK YOU!