I have always found this helpful:
Please address group e-mails BCC (Blind Carbon Copy). What this does is hide the recipients e-mail addresses from each other. This way all of the recipients don't get each others' e-mail addresses and they don't end up getting sold and spammed out of existence. Most people will appreciate it if you do this. Some mail software makes you put at least one e-mail address in the regular mail to. If that's the case, I just put mine there since everyone I am mailing will have my eddress anyway.
I usually take a second to delete any other e-mail addresses that might be in an e-mail sent to me before passing it on also. This is easy to do by copying and pasting the e-mail contents to word pad. I remove FWD & FW from the subject line too. I feel if it isn't worth showing that much respect to the people I send it to, why should they bother to spend their time reading it?
Hope this is of help to you and you will pass it on, Blind Carbon Copy!
Posting it on facebook and MySpace is a great idea too!