I have a violin sitting at home that I had a couple of lessons on last year but didn't really get started on..... in the interests of playing something more unusual I've decided to re-string it as a viola (I'm teeny so even if/when I buy a proper viola it would not be much bigger!!). Any suggestions for good tutor books for someone teaching themselves please?

Ta!

There's no good way or book to teach yourself a stringed instrument, you just have to have a teacher. Even if it's only a 30 minute lesson once a fortnight, make the investment and go with whichever book they suggest as they probably know what they're doing.

Well done for making the switch btw!

Yes, you definitely need a teacher to get you started. It's important to get the right techniques and not get into bad habits. I'm not sure about viola technique books, but good violin books are Suzuki Method, Fiddle Time Sprinters, Herbert Kinsey technique books, Neil Mackay books, Abracadabra Violin - I'm sure most of them will have a viola version of the books.

Have fun learning!