The life of St Dominic

http://books.google.com.au/books?id=E9jBRnhli_0C&printsec=frontcover&dq=st+dominic&cd=2#v=onepage&q&f=false

St Thomas Aquinas

http://books.google.com.au/books?id=WKWrcNJyGL4C&printsec=frontcover&dq=st+thomas+aquinas&cd=3#v=onepage&q&f=false

Catholic library with Links to online books of saints

http://www.catholicapologetics.info/library/onlinelibrary/index.htm

Our own website also has some great readings on saints and a great introduction to Dominican saints

http://www.dominicans.org.au/saints.html