It depends on what style you want to play. I think a good starter is "Pattern Picking" by Happy Traum. It is put out by his company Homespun Tapes. It teaches generic picking patterns that are suitable for accompanying folk songs as well as some sample songs. These are usually well-known songs such as: Red Apple Juice (Ain't got no honey baby now), The Butcher's boy, Nine Hundred Miles, Railroad Bill, Freight Train and a few others.

My copy consists of tapes and a booklet, but I think you can get a CD in place of the tapes.

If you go to the site, you can look at the other beginning books he has on offer.

Murray