For a good place to begin,go to a good book store (like Barns & Noble or such ilk) & for about $15 pick up the Klutz Press book & tape "Country & blues Guitar for the Musically Hopeless" Written by Carol McComb. You won't pick like Doc Watson, but you'll have a good handle on the basics & even if you get a teacher, it would still make a good text book.
By the way they have one on playing the Harmonica too & that's how I learned it.
Good Luck Charcloth