Forgive me for asking, but I presume you have a work permit, as far as I am aware all US nationals need a work permit to work in the UK.
And also what kind of work you want to do? Do you want to still be a nanny? Does your partner still want to work as a bicycle courier? There's not much call for those in Devon and Cornwall - it's much too hilly!
If you want to be in or near to a city then you should consider Plymouth or Exeter, both in Devon. That's where you will find the good night life, more possibility of a job and you will also be close to the countryside and the sea.
Check out
http://jobs.thisisplymouth.co.uk/
and
http://jobs.thisisexeter.co.uk/
I used to live in Devon and whilst it, and Cornwall are beautiful counties they do still have problems. Housing is very expensive as many people buy houses there for second homes meaning that the locals are priced out of buying. Many jobs are within the tourist trade, meaning that they are low paid and often seasonal. Both Devon and Cornwall have large farming communities, some of which have been devestated by recent disease outbreaks (foot and mouth) plus down turns in the farming world. Many, many people in Devon and Cornwall live below the poverty line.
Have you ever visited Britain? It may not be all you think, though to be fair, Devon and Cornwall have the quaintness that Americans love!
I have a friend in Kentucky who lived in Devon for three years and thought she was in heaven!