Thanks for the tips guys! The links to other recordings were particularly helpful. I wonder of it is such an oddity that I didn't know this tune already? Perhaps as an English folky, I've been less exposed to that kind of music? Oh well, I certainly know it now!
So, having mastered Oh! Susanna, on left hand, then right hand and then playing in octaves, I moved onto lesson two which was Oh Susanna, using very simple harmonies on the left hand (just playing which ever key was left of the melody key). This is simple enough, but to me it just sounds like I've got fat fingers and I'm hitting too many keys, even if it is intentional. (Again a video of someone doing this well would be very helpful to folk like me who have bought the tutor as total beginners).
I've started trying to play the second tune in the book too, Shepherd's Hey. A tune that I recognised, hooray! I'm rather confused by the instructions for the left hand chords though. The way I'm stabbing at it, it sounds bitty and like I'm doing something wrong. Also the second chord, an F, doesn't sound right to me at all... maybe I'll get this, as I persevere, but at the moment I'm pretty confused by what it's meant to sound like and Garry Coover hasn't put a video of this on his page either. I suppose Mr. Coover's assumption is that these first couple of tunes are simple and commonly known, therefore unnecessary to put up videos, but I would suggest that as the first two tunes in the book it seems essential to have good videos of them on youtube. These are the tunes that you're using to master all the most basic techniques to carry on your playing, so getting them right to begin with is, in my eyes, pretty important.