Planning the Winter Garden

I've never grown a winter garden, so this is going to be an experiment and adventure.  Since our winters are generally mild in 7b, it seems that it should be possible to grow some cold hardy veggies.  I think it'll be fabulous to have fresh vegetables in the middle of the winter.  I've been daydreaming of fresh salad in December.  To try and make this dream a reality  I am reading The Winter Harvest Handbook by Eliot Coleman.  It's amazing how much he grows during the winter in Maine!

So if it's possible in Maine, it has to be doable in SC.. right?  My concern is that with cold nights, but daytime temperatures much higher than in Maine, I could end up cooking my winter crops under plastic.  I also found this article on Extending the Salad Season helpful because it is in Zone 7.  Based on this article I decided on Agribon+ AG-19 row covers and ordered a 10' x 50' row from Johnny's Seeds.  This is far more than I really need and of course my first thought was to increase the number of winter garden beds.  I was originally going to have one or maybe two, but with that much row cover material I could have five!  Then I had to tell myself not to go overboard since I've never grown winter crops- start out small so that it isn't overwhelming. 

Step one of winter gardening is now complete: order row cover.  The next step is to decide what to plant.  I did order a few seeds along with the row covers: Napoli carrots and Pak choi, which were recommended in The Winter Harvest Handbook and Easter egg radishes because they look so pretty!  I am concerned that the salad garden in Zone 7 was seeded in September.  I hope to get mine planted by the end of October and hoping that's not too late!

If anyone has any suggestions about winter gardening- what to plant, when to plant, or any words of wisdom- I'd appreciate some guidance.