How do I set up a group contact for email in Outlook 2007?

I'm somewhat new to Outlook. Had been using Outlook 2003 for contacts and
calendar but still using Eudora (sponsored) for email. I've now bought a new
computer and using Outlook 2007 (& Win7) for all.

I also sync with my Windows mobile phone.

I send out a support group meeting reminder as a volunteer. I have 21 email
addresses on the list currently. I do not know most of the people. In Eudora,
I had one contact with all the email addresses in the 1 contact. I would like
to do the same in Outlook 2007, especially since I sync and don't want to
clutter up the contacts on my phone with people I don't even know.

How would I do this?

Also, so far I haven't found a manual for Outlook to look up individual
questions like this. I guess there isn't one to download, just tutorials?