Hi Kim,
I just got my first bin over the holidays as we drove to GA to visit our son. Since I live in central OH and had neglected to follwo thru on ordering worms in warmer weather, I was in the same boat as you. On the way back I connected up with a seller I found via craislist.com and now have a 30-gal bin w/2lb of wonderful little wrigglers!
So try craigslist in your area for possibilities, but even better may be this link & the one below: http://www.findworms.com/directory/index.php
I find the Vermicomposters site a tad cumberson and slow to load, fiddly to navigate around (IMHO), but has the most comprehensive sources. Just plug "Michigan" into the search box; you will see LOTS of fellow vermiphiles in your state! And of course, lots of pages of info and discussion. You might find a bait shop with worms--but then again I don't know if they sell them in the winter!
Happy wiggling! :-) CK

Here is a link that might be useful: Vermicomposters