Charley: I like the notice posted at Filk Music Blanket Permission List" The link is to allow you to see it on-screen, but I also quote it here:
"The following folks have given blanket permission to post their songs, so long as proper credit and copyright information are kept with the song, and it is not published or recorded for sale without specific permission from the writer. If a writer is not listed, check with them first. See also the above list."
Whilst this is meant to refer to numerous writers, it ca be easily re-vamped to cover just your own material on your own site. If you are planning a 'page per song' I would suggest you use something similar as a standard 'footer'

CHEERS

Nigel