Rhonda -- I've personally never been very comfortable using Yahoo Groups and for our purposes, Yuku.com and Aimoo.com may be a better choice because they have a similar "forum" style, with the "rooms" on the left side and the messages inside those rooms. Most MSN groups are moving to either yuku or aimoo.
We can always do a trial run on Yahoo. If you want, why not set up a group at Yahoo and then we can test it out. The reason I also was favoring aimoo.com is because they have a feature where they can migrate this group, which would mean (if I'm understanding it correctly) that we would be able to keep all our old posts and they would set up our group for us. But if you want to do a test-run at Yahoo, go ahead ... we still have about 3 weeks to decide, so we can play around with different forums in those 3 weeks and see which one everybody likes best.