Hi, Suze. Daividh is currently in the process of moving house, so if you don't hear from him right away, that's why. :)
Have you tried accessing
www.amazon.com to do a book search or ordering on-line?
http://www.amazon.com/exec/obidos/search-handle-form/107-6430137-8476561
I don't know which book Daividh used as his reference and, unfortunately, all the Welsh name books listed on Amazon's site are now out of print. Daividh may have been using a book on saints to find "Ninnoc" for you, as that name doesn't happen to appear in my own book of Welsh names: *Enwau Cymraeg i Blant: Welsh Names for Children*.
Keep checking the board here periodically. I'm sure Daividh will direct you to the right reference source when he gets back, and possibly one that you may be able to order over the 'net. :)
-- Nanaea